The story of Valeria Richards begins during Sue's (Invisible Woman) second pregnancy. Due to her exposure to the cosmic storm, Sue's pregnancies have always been difficult, as was her first born Franklin's and now Valeria's. Because of her body becoming weakened, Sue gave birth to a still-born daughter. (The trauma of losing her daughter would eventually trigger her transformation into Malice.)
In reality, Franklin used his vast psionic abilities after feeling a part of himself missing, guided by Roma, a guardian of the Omniverse. Franklin went back in time and managed to save his sister's life before she was born into the world. He sent her "some place else" and for years both Reed and Sue believed their daughter to be dead.
Valeria's first appearance in comics was a cameo as and adult Valeria von Doom in Fantastic Four vol.3 #15 in March 1999, during Chris Claremont and Salvador Larroca's stint on the Fantastic Four. Her first full appearance as an adult was in Fantastic Four vol.3 #20 in August 1999. Valeria as a child makes her first cameo in Fantastic Four vol. 3 #50 (seen in the belly of Sue Richards), and her first real appearance in Fantastic Four vol.3 #54.
Major Story Arcs
Marvel Girl aka Valeria Von Doom
A few years down the line, a girl appears out of nowhere at Pier 4, during the Fantastic Four's stay at the location after returning from the Heroes Reborn Earth. Everyone, naturally, is wary of this new girl, but Valeria remains optimistic. Franklin is one of the first to accept and believe in her story, creating a very strong sibling bond, although in this reality she is the older sibling, while Franklin is the younger.
During the course of her stay it is revealed that in her reality she was the daughter of Victor Von Doom and Baroness Susan Von Doom (the Susan Storm of that timeline), which causes a large rift between mother and daughter.
Susan believes that Valeria is lying, and is a part of one of Doom's ploys to get back at the team. At the same time, she refuses to accept the possibility that she will marry Victor one day, and since Valeria is assumed to be the a result of that union she must in turned be denied. Reed decides to make a few tests to see if what Valeria says is true but Susan doesn't want any of it, and goes as far as calling her daughter a "monster".
Valeria overhears her mother's harsh words and runs away, only to find herself in a dangerous situation involving a mind controlled She-Hulk, Absorbing Man, and Titania, with the Thing eventually joining the small gathering. Valeria manages to fend them off long enough for the Fantastic Four to come to her aid. Sue valiantly fights all four super-strength brutes, and accepts Valeria as a friend and invites her to stay with the FF at Pier 4. Valeria and Franklin's relationship only grows during this time. Valeria remains with the Fantastic Four for the majority of her stay in that reality. She even meets Doom along the way, trying to get her "father's" attention but Doom would have none of it.
A strange phenomenon is soon felt by the gang and they soon learn that the Heroes Reborn Earth is trying to merge with the regular Marvel Earth. As a means to save both Valeria and Franklin, Sue commissions a ship to send the siblings away in. Both she and Franklin eventually find themselves on the other side of the universe at a school for the gifted. There Sue learns from Franklin about Roma, a woman who he'd seen in her dreams and was helping him rectify what was about to happen. This was around the same time that the head of a Galactus from an alternate reality appears in New York. Franklin and Val eventually return and find themselves thrust into a confrontation that would determine the fate of more than one world.
Upon returning, the truth about Galactus' and Abraxas existence is revealed. Galactus exists to keep the Abraxas of each reality prisoner. Unfortunately, because the Galactus of an alternate reality was already killed, Abraxas was free and able to cause mayhem. As the Fantastic Four travel from dimension to dimension trying to find pieces of the Ultimate Nullifier, Valeria helps in any way she can. After nullifier is found they were betrayed by Nova, who was actually the herald of Abraxas. The situation seems dire and then something happens which awakens Valeria and Sue to the truth. Both mother and daughter share visions of Franklin and what he did in order to save Valeria's life, and finally Sue accepts Valeria as her daughter after learning the truth.
Seeing that Abraxas was hard to defeat, eventually Franklin and Valeria combine their powers to restore Galactus to life, realizing that Galactus was in the heart of Eternity. In the process of that plan of attack, Valeria's life is forfeit. Or is it? Moments after the event, Sue is shown calling out to Franklin and carrying a rather large bulge.
Valeria's life once again returns to that of a baby inside her mother's womb, making Sue once again pregnant with the baby girl she thought she lost many years ago. Now the truth of Val's father is revealed. Her father is Reed Richards ( Mr. Fantastic) and not Doctor Doom. This was a gift bestowed upon the team as a thanks for saving the worlds from possible annihilation.
When it comes time for Sue's pregnancy to come to term, she finds herself in a difficult position. Her body is once again weakening, just as it had the first time. Johnny Storm ( Human Torch) seeks Dr. Doom' help since Reed is unavailable due to an encounter with the Hidden Ones and is trying to avert a crisis.
Surprisingly, Doom agrees to deliver the child on the condition that he be able to name her. Sue realizes that both her life and that of her child are in danger and agrees on the terms, although she's very reluctant. Doom manages to deliver the baby girl safely using both science and magic and he names her Valeria after an old love. But unbeknownst to Sue or Reed, he also places a spell on the child, thus making her his magical familiar. This action would later result in the Fantastic Four living through one of their worst ordeals.
About two years later, Doom takes advantage of the spell he cast on the child, and thus carries out a surprise attack on the Fantastic Four. In the course of it, Franklin is kidnapped by demons and sent to Hell. Valeria is heard uttering her first word, which is "Doom". The gang goes after Doom to "cure" Valeria and find their son. Unfortunately, it is to no avail, Doom's magic is too powerful and he takes Valeria while the Fantastic Four suffer an ordeal of living painful versions of their teammates' powers.
Eventually, with the help of the astral projection of Doctor Strange, Reed is able to free himself and his teammates and they manage to rescue Franklin and Valeria. At the same time they free her completely from Doom's grasp and end her bond with him as his magical familiar.
For a time following this, Valeria lives as normally as one can live with world-famous super parents and family members, acting like many other children of her age.
Later on during the "Death of the Invisible Woman" arc it is revealed that Valeria has already been exhibiting her genius-level intellect through a conversation she has with her nanny, Tabitha Deneuve. Tabitha in reality is the future self of Sue. When the Baxter Building is under attack and Sue tries to protect Valeria and Tabitha, she is unaware that Tabitha was the one that set off the attack. Sue is knocked out by Tabitha's more powerful force field powers. When Tabitha is about to escape, Valeria follows her and asks her why she's doing this. And that's when Valeria reveals to everyone that Tabitha was Sue from the future.
After reviewing the events of what happened when Future Sue attacked, Reed watches video footage of Valeria and before the team goes off to fight the team of future super powered individuals, he exclaims to Valeria that he needs to speak to her.
Later it is seen that Valeria has let her intelligence loose full force. Sue finds highly advanced books in Valeria's book stand. Along with that, Valeria is seen following in her father's steps by creating some highly advanced inventions.
Through some means the Invisible Woman "vanishes" and as a result Valeria and Franklin go to seek help from the mutant detective Agency, X-Factor Investigations. While there explaining the situation and showing her superior intellect, Valeria reminds many of the members of a young Layla Miller, and freaks out Darwin. They bring the group to the Baxter Building where they half got into a fight with the Thing to provide a distraction, and the other half get the needed information.
Her intelligence growing vastly, Valeria is met in the Baxter Building by a strange invader, that she of course realizes is her brother Franklin from the future. He warns her of a pending crisis known as the 'War of the Four Cities' and tells her that to save her father "All hope lies in Doom." Valeria discovers the portal her father secretly created and goes through it, finding The Council, a collection of many alternate reality versions of her father. They are being destroyed by the Celestials and three of them manage to escape through with Valeria to her home.
Realizing the threat they pose and making the connections to what her brother warned her of, Valeria secretly went to get Doctor Doom's assistance, only to find him in a state of brain damage (from the World War Hulks story arc). She made a deal with Doom - help her save her father and she would help restore his intelligence.
Around this time, Reed brought Valeria and a group of other gifted youngsters together to help solve the problems of the world - which would be known as the Future Foundation. But even their great minds could not solve the problem of the invading Annihilation Wave and they could not close the portal to the Negative Zone. In order to close it, the Human Torch sacrificed himself. This caused much anger in Valeria, who began coming up with plans to kill Annihilus.
After speaking with her grandfather Nathaniel, they introduced the induction of Doom in to the Foundation, much to the dismay of the remaining members of the Fantastic Four. Along with many other great villain minds, they began to form their plan to stop the Council from their devious plans.
Ultimately, the Valeria and Franklin of the future returned to help stop the Council and the Mad Celestials that were attracted by their schemes.
Valeria chose to move to Latveria and reside with Doctor Doom. She planned to turn Doom into a force for good, which seemed to be working. With all the distrust she now had for her father, it seemed like the right choice for the time. When her mother attempted to take her by force from Doom, Sue began to show signs that Malice was returning to her psyche. While she originally refused to return home, she eventually decided that her family needed her.
Powers & Abilities
As Valeria Von Doom (Also Known As Marvel Girl)
Force-field generation much like her mother, which means she has the potential for an unlimited power source. Her only only limits are her own imaginations and reservations.
Time manipulation via a "Time Dance".
Able to transform into an armored state, whose armor is similar to Dooms.
Genius level intellect on par with Reed Richards (her biological father).
Since Reverting Back To Childhood
None, but it should be noted that she's still a child, and might not exhibit her powers until she hits puberty like most mutants.
Valeria even at such a young age has a genius level intellect, matching or surpassing her father's. She does have access to, and the ability to create, technology greater than most. She has a levitation jacket that she used when she and Franklin went to X-Factor looking for their mother.
In Marvel Knights, Johnny encountered a "future" version of Valeria who had an advanced form of her mother's invisibility power. Using her powers she was able to truly make a person invisible, hiding the person's kinetic energy, thermal energy, etc.