Just heard from herself -- it is indeed the 3 magi. It's often true in Italian Painting that youths are feminized. You've also got the symbolism of the 3 ages of man -- youth, middle age, and Old age. Frequently, but not always, you've got 3 "races" as well -- European, Asian/Arabic and African. It's just an indication of Exoticness and Foreign-ness.

The 3's give it away -- 3 halo's, 3 gifts, 3 crowns, etc.