I'm sorry you have to switch! I guess there's no way you can stay with her?
As far as gifts go, I've given my psychologist & dietician (but not psychiatrist, because I'm not as close to her) gifts, too. What are some things she likes? I was about to suggest having someone take a picture of you two together & you could frame it (& get doubles so you'd have one, too) to give her; it might be hard though, with privacy issues.

What about a gift certificate?