Suggestions on a thank you gift for my boss?

So I recently graduated from college and since my sophomore year I have been working as a student assistant in my major school. I have yet to find a full time job, so until I do, my old/current boss said that I could continue working the student assistant job (even though I technically am not a student anymore) by hiring me as a temp. Through my entire time working there, with all of my ups and downs and setbacks, she has always reserved a place for me there and ALWAYS makes sure I get plenty of hours. She has been a shoulder to cry on and has been super supportive of me. She always has looked out for me more than any of the other assistants, and when I leave at the end of the summer I wanted to give my thanks. I’m giving everyone in the office thank you notes, but I really wanted to give her something extra (that wasn’t a gift card). I’m just not sure what to get, especially since I need to keep it within a pretty small budget. Any suggestions?