Don't know what you're looking at in terms of budget, but my dad, God rest his soul, took me skydiving for graduation. Not as expensive as you might think, and I promise that she'd NEVER forget it. I realize leaping out of aircraft isn't for everyone, but I thought it couldn't hurt to chime in with what for me is a very special personal memory.
Another idea that I just did for my daughter on the occasion of her 8th grade graduation (coming up next week actually) was to find a picture of something we did together when she was a toddler, sort of a "first", like a first trip to the zoo, etc., and then return to the same location and revisit the activity again together. In my case, I found a picture of her and I the first time I took her to Dairy Queen when she was 2. We went and had ice cream together, had an employee take our picture in the same spot we were in 12 years ago, and then I made an 8x10 side by side collage of the two pictures, printed it and framed it for her. She loved it, and even shed some tears. Without a doubt the best $25 I've ever spent, inclusive of the frame and the ice cream.
Good luck, and congratulations on your little girl reaching this significant milestone in her life. My son will be reaching the same milestone soon, and it's been a real challenge dealing with the idea of entering the "empty nest" phase of my life, but that's another discussion entirely!
Have a great evening.....