Muses can be hard to positively ID, but I’m pretty sure this one is Terpsichore, Muse of Dance. She is sometimes shown dancing, and sometimes, as here, as a seated woman in Greek dress playing her harp to accompany a troupe of dancers. Presumably the laurel wreath hanging from the back of her chair will be awarded to the best dancer.
Terpsichore is about 8 inches high and made of spelter, an inexpensive white metal alloy made mostly or entirely of zinc. Originally used as decoration on an Ansonia clock, she was made in imitation of costly French bronzes of her day.