According to her Wikipedia article, “Anne Emily Innes-Ker, Duchess of Roxburghe VA OBE (née Spencer-Churchill; 14 November 1854 – 20 June 1923) was the daughter of the 7th Duke of Marlborough, who served in Conservative governments as Lord President of the Council and Lord Lieutenant of Ireland. She served as Mistress of the Robes to Queen Victoria…” She was the daughter of Lady Frances Vane and the grand daughter of Frances Vane, Marchioness of Londonderry. She was also Lady of the Bedchamber to Queen Victoria.
The left image is from pinterest.com/pin/242561129907036194/, the right image is from pinterest.com/pin/502362533411414854/. Also posted to The Belle Epoque - 1890 - 1914 Album here.