Gift ideas for college graduation?

A friend of mine who I've barely seen since high school is graduating this semester and invited me to her party. I know her interests have changed a lot since high school and I'm not sure what to get her. She still lives with her family and has allergies, so perfume is out. She's into holistic stuff, which I know nothing about, and she doesn't drink. We aren't really close anymore, but used to be best friends in high school. I'm trying to keep under $20 since money is tight.Any ideas?