SQL for dummies is a good book to start with the ISBN number is 0764501054 it might have a bit of an off putting name but it is clear and easy to understand; from this book she should be able gain a good understanding of how to use mysql and it does not get to technical for beginners.

this book helped me and a few of my friends while we where in uni just getting to grips with mysql. the more advanced books just take it that you already know the basics which is never good when you start out.

i could do with getting another copy of it i need to brush up on it myself.