Hi A.,
I love the framing idea, but it can be pricey.
My husband just graduated last weekend with his MBA. So he's married, with a career and just completed this milestone.
He received money, Best Buy gift card and homemade things from the kids. I bought him the video of the ceremony for him to show our family who was not in attendance. (you need to contact the university to see if that's available) He attended on-line, so graduation on the actual campus was a big deal...he bought lots of things at the book store. (A gift card to there for "Alumni" merchandise?)
My husband appreciated any acknowlegement of his accomplishment. It is a huge deal with a marriage, kids (if any), and a job. She has most likely been studying quite a bit away from the family, so a gift card to a night out may be nice, too.
Just knowing that you care enough to do something to acknowlege it is great, I'm sure she'll appreciate it.
This was rambling, but I hope it helps in some way.