I would take her on her dream vacation I think! I have asked my parents before where they would go if money was not a factor. I found out where she would love to go this way, and I would take her there, or send her there. It would be even better to take her and spend the time there also I think!
Another idea is to buy her some beautiful jewelry with her favorite gemstones in it. I think that is a lovely idea, that and some beautiful flowers, or a shopping spree!