Does she have her Driver License? a car?
A nice keychain. My daughter (18) got a really nice little wallet off Etsy that has an enclosed pocket for the cell phone, zippered area for money, credit cards and id. She can clip her key chain on it and everything is in one place and it has a little wrist handle. Really cute.
jewelry.. depends if she likes jewelry or not. When our daughter was younger we got a couple of nice rings for her (she picked them out) a couple of nice necklaces. For high school graduation, one of her gifs from us was a beautiful David Yurman ring she selected.
Class ring? I think the popularity of these are dwindling but in some areas, they are popular. Our daughter opted not to get one and that is why she ended up with the David Yurman because it is a classic that will never go out of style like a class ring does.
ITunes, gift cards to movies and shops, spa day, lotions, mani/pedi items, books, nice pair of boots, silky pj's, soft socks
Hope something hits your target there!!