I cannot resolve the identity of the artist, but the engraver is J. W. Cook.
Posted to marie-antoinette.forumactif.org/t114p225-portraits-de-la-princesse-de-lamballe by La nuit, la neige on 3 November 2015; monocolor tint removed. Also posted to Maria Teresa Luisa of Savoia, Princess Lamballe’s Subalbum here.
The Princess may be wearing a wig adorned with flowers and feathers as a het secured with a strap around her neck.
Keywords: Cook, Maria Teresa Luisa di Savoia-Carignano, Marie-Thérèse-Louise de Savoie, principessa di Savoia-Carignano, princesse de Lamballe, Mademoiselle de Carignan, Madame de Lamballe, Savoia-Carignano family, Bourbon family, Princess, French, Lady-in-Waiting, Marie Antoinette, curly coiffure,curly wig, feathered floral headdress, earrings, strap, bows, fichu, vee neckline, lace bertha