What should i get my girlfriend for her birthday ladies any sugestions?

My girlfriend jeannies birthday is comming up next week i was wondering what would be a good birthday present for her. She is rich and has everything she needs. She works at a buffet place in sioux falls,sd. She has been a god send to me she has such a wonderful personality. i want to buy her some longerie but feel uncomfortable asking her her sizees How do i go about doing this in the right way. ladies any suggestions thank you