This is a George Stuart figurine of Queen Henrietta Maria wearing a white dress with a lace collar, probably from 1636. Her dress most closely resembles this one.
Keywords: 1636, van Dyck, Stuart - George, British, Stuart family, Bourbon family, Queen, Queen Henrietta Maria, curly coiffure, high neckline, collar, lace, jacket bodice, puffed sleeves, crown, necklace, draped necklace, earrings, jeweled bodice ornament, jeweled crucifix