How about a gift certificate for a pedicure at a local nail salon? It should be easy to find a good one on Yelp or something.
You could also send her books with a gift receipt, so if she's read them or has different taste, she can easily exchange them for something she likes better.
Gift certificate to amazon or itunes.
You could also send something that she'd be able to use for her upcoming wedding - a picture frame with a note inside (where the photo would go) that says "wedding picture here," pretty champagne glasses for their toast (my sister got me beautiful ones for under $5 each at BevMo), cute lingerie or a garter, etc.