Sorry, don't purchase New 52 Action Comics on a regular basis but in one of the earlier issues I've read was a character named Susan.... a young girl, that was somehow connected to Superman's conscience or something? Can anyone give me any information on her or which issues of Action Comics she appeared in.

Tried to wiki the character but gave up after the 5th page.

Lois' niece?

Right. Lois Lane niece.

She appeared very early in the New 52 Action Comics. She wasn't connected to Superman in any way, she was what they called, an Ultra-Sapien. Basicaly ultra-sapiens are beings not exclusive to humans, but to many races, each one representing a leap of hundred of thousands of years in each specific race evolution. Her powers like those of another human ultra-sapien were mainly psychic. Although the other one, who came to be known has the first Superman, I'm not entirely sure his mutation into a ultra-sapien was natural or caused by Kal-El ship, the day he arrived on Earth.

Because the teams of writers and artists are always changing we saw a great leap to the future, the ultra-sapiens and Susy were forgotten.

Although more recently in the Future's End stories there's a girl with immense psychic powers that calls herself Fifty Sue. Don't know if it's the same girl or some crazy clone of hers. One thing is certain Fifty Sue is all ways crazy.

Hope this gave you the info you seeked.