From Wikimedia.
Zinaida Yussupova wears an over-dress with a deep vee neckline filled in by a chemise and possible lace jabot in her 1840s Robertson portrait.
Keywords: Robertson, Zinaida Yussupova the elder, Yusupov family, Russian, long straight coiffure, jabot, lace, chemise, trapezoidal neckline, over-dress, vee neckline, long tight sleeves, vee waistline, full skirt