Traditional suggestions for a classy girl:
1) a sniffathon in a mall,
2) a set of 3-4-5 miniatures (to further explore Chanel, or something new for her: Dior, Guerlain, Hermes, Estee Lauder, Annick Goutal, many are available via Internet),
3) ask her what she wants this time: as based on what she already likes it would be florals, aldehydes, sweet perfumes with woods or spices. Another bottle of Mademoiselle in perfume concentration? Or, perhaps, she's got a couples of girls at work or family members whose fragrances she likes and wants to try on herself. Unlimited possibilities..... Somehow I think of JPG classic or Fragile, I do not know why.
Good luck!