Her house is full with piles of books. One could say 'no one can possibly live here'.
She was a librarian at the First Branch of the Central City library. But when she was at the Central City library she forgot she was supposed to be working, and read books instead. And as one could expect; she got fired.
But when the Central City library burnt down she was the key to the books that got lost in the fire. Because Sheska is gifted with the talent to remember and reproduce anything she has ever read with word-for-word accuracy. And therefore, she got hired by the military again.
When looking at the fact that Sheska has collectors mania, and forgets anything around her when she reads a book and last but certainly not least her extra ordinary talent to reproduce books she read times ago, one could conclude she has savant autism.