Sybil,
All About Eve
One Flew Over the CooCoo's Nest
The Bell Jar
(Those are all novels which will give good understanding of the field and develop empathy.)
The Idiots Guide To Psychology

I would suggest a Social Psychology text, if you choose a text book, too. It's far more interesting and you can do some cool experiments with the student. An introduction to psychology is usually a bit dry, and will probably turn her off.
Just my opinion, of course.

Peace!