The Wikipedia article for the Belosselsky Belozersky family's palace has this about her, "Alexander Mikhailovitch' second wife, Anna Grigorievna (born Kozitskaya; father Secretary of State to Catherine II, Gregory Vassilievich Kozitsky; he was also rector of Moscow University. Anna Grigorievna's portrait by the well-known French and Russian court portrait painter Vigee Le Brun is in Washington DC's National Museum of Women in the Arts) was an heiress of a great fortune through her mother, Ekaterina Ivanovna Myasnikova (major south Urals area metals and mining heiress from the Myasnikov-Tverdychev families, e.g. Yuryuzan, Ust-Katav, Katav-Ivanovsk, Nizhnyi Tagil, Beloretsk)..." Élisabeth Louise Vigée-Lebrun passed in 1842 so this is one of her later works. Anna's sister Alexandra married Ivan Laval, a French emigré to Russia.
From the Museum Web site; upper edge fixed with Photoshop.