Rapunzel had been cursed by Frau Totenkinder for displeasing her and for being 'slutty little girl. In 1001 Nights of Snowfall, Frau apparently said she would be in the tower for the rest of her days. Rapunzel's hair is constantly growing, at a rate of four inches an hour. Because of this she has to live under the most restrictive conditions of any of the city Fables, to prevent any mundanes from noticing the fast growth. She has three haircuts each day, which Joel does for her and donates her hair to charity. She was part of the group of Fables who were part of the last stand in the old territory and so she is also present at the Remembrance Day for those who died in the battle at the Last Castle.
Cinderella: From Fabletown with Love
It's revealed in Cinderella: From Fabletown with Love that Cinderella's Fairy Godmother showed Rapunzel's prince the way to the tower that Frau kept her in, mainly to spite Frau. It's unknown of her Prince's whereabouts or if he's still alive.
In Fairest The Hidden Kingdom, the story's set before Charming took over as Mayor, when Jack was still in his on/off again relationship with Rose Red. Its revealed that Rapunzel remembers Frau Totenkinder and doesn't believe at all that she's "reformed". For obvious reasons, she has an almost utter disdain for the old witch. Despite their history, Rapunzel still calls her "mom" but it may only happen when she wants to get on her good side. In the story, its revealed that Rapunzel had two daughters and strongly believes them to be alive and had been stolen by a midwife. We also see more of her relationship with her Prince, that Cinderella's Fairy Godmother had led to her. Frau eventually discovered she was sexually involved with the Prince and apparently banished her from the castle tower.
Rapunzel does know some of Frau's past, including how she "gave up" her son. And that Rapunzel's biological mother had sold her to Frau in exchange for a handful of gold and rapunzel leaves to be a witch's apprentice. Frau had often told her, that she saw Rapunzel as a second chance. The young pregnant Rapunzel would spent months looking for her prince, and ultimately gave up. However, he did not abandon her, not by free choice. Unknown to her, Frau's rival of sorts Fairy Godmother was behind their separation.
She threatened him to turn him into a frog, should he try to go to her. Fairy Godmother had plans for her, what plans are yet to be seen. It is a possibility that the Fairy Godmother may have been the midwife. One hint is that she gave Rapunzel an apple to ease her pain during labor. In Cinderella: From Fabletown with Love, the Fairy Godmother had admitted she and her sisters had a weakness for apples. Whomever the midwife was, did help deliver her twin girls then stole them. Though due to the drugged apple's effects and most likely her exhaustion from labor, Rapunzel was too weak to take them back.
Ultimately believing it was Frau, she tried to confront her when she regained her strength. But the tower was gone, along with Frau Totenkinder. Rapunzel then ventured through various worlds in the Homelands searching for her twins. She went to great lengths to find her twins, soon becoming a warrior that even killing a minotaur. But she never found her twins. Heartbroken and feeling abandoned, Rapunzel had traveled to the Hidden Kingdom; one of the lands Japanese Fables had inhabited in the Homelands.
She mostly likely traveled, hoping to go to the edge of the world and die. However, she had been saved by the Funa yurei (Japanese spirits of the drowned), dressed her up, and got her through the fortifications of the Celestial Palace. The Emperor welcomed her to stay as a guest. There she had a romance with a female kitsune named Tomoko. But the romance was short lived, as the Emperor was being manipulated into banishing all demons from his kingdom. His shogun, most likely did it to take away any threat for when the Adversary came to attack in the future. Due to Tomoko being a kitsune, he banished her and took her foxfire (which was part of her soul) away from her.
However, no one in Fabletown, especially Snow and Bigby Wolf believe her. Her story begins when she gets a strange message during one of her haircuts and is covered by origami paper cranes, one with a message in Japanese. When she realizes its about her children, she pleas to Snow and Bigby for help. However, Snow quickly refuses to believe Rapunzel's ideas. Bigby does try to bring up the factor that their could be another gate, Snow still dismisses it. With coaxing, she gets Joel and begrudgingly Jack Horner to accompany her to Japan and contact an informant. The arrival isn't an easy one as they are quickly attacked by what appears to be a Kuchisake-onna demon.
Unexpectedly, she and Tomoko reunited, not fully knowing her former lover was part of the yakuza. There she introduced the group to her "Fabletown". For yet to be explained reasons, a kappa is trying to reunite Rapunzel with her children but also keep her separate. Hinting Tomoko staged the attack by the demon to get Rapunzel closer to her. When Rapunzel tries getting answers from Tomoko, she quickly tries to make Rapunzel "forget" her children and stay with her. While tempted, Rapunzel refuses to give up her children and quickly asks if she knows where the gate is. When Tomoko doesn't answer, she takes a drunk Joel to their hotel. Unknowingly, Jack separates from her to go find something worth stealing.
Sensing something wrong, she seduces Joel and the two have sex. Much to his dismay, he realizes she only slept with him just so her hair could grow. She admits it but also admits that also as a means of escape as there were cameras everywhere in the building and yokai guarding the entrance. The pair are eventually given aid by a cat demon and are taken to Tokyo station. He left them instructions to go to Nara, with hopes she'd find her "children". As they prepare to go, Joel is still angry over what happened back at the hotel.
Whether feeling like their friendship had been used or that she had toyed with his feelings, he accuses of her treating him unfairly, despite his loyalty to her. He then leaves, saying he was sick of cleaning up after her. But as she finally reaches Nara, she finds Joel there waiting for her. The pair reconcile and as they walk Rapunzel goes more into detail about her past to him. As they venture to through the forests of the temple, they come upon what appears to be a well.
Rapunzel stops dead in her tracks, she then explains to Joel the message they received. The message "your children", didn't mean her daughters. It meant her revenge and as she explains Mayumi the Kuchisake-onna demon prepares to attack them.