K.D.
I also have a best friend of over 20 years and if it were her I would fly in her aunt and grandma for the graduation and afterwards take everyone out to a fancy restaurant to celebrate. At the restaurant present her with a tennis bracelet or something to show how much I love her and how much she means to me. It's just a thought and what comes to mind because good friends are more like sisters and those are hard to find! :-)