She had a total of 11 children, and her principal home was the monumental Blenheim Palace, which she rejuvenated with her "lavish and exciting entertainments",[1] and transformed into a "social and political focus for the life of the nation".

Lady Frances Anne Emily Vane was born on 15 April 1822 at the Duke of St Albans's house in St James's Square, London, the eldest daughter of Irish-born Charles Vane, 3rd Marquess of Londonderry, and his wife, heiress Lady Frances Vane-Tempest.

She had an older half-brother, Frederick Stewart, 4th Marquess of Londonderry, by her father's first marriage to Lady Catherine Bligh.

On 12 July 1843 at St. George Street, Mayfair, Lady Frances married John Spencer-Churchill, Marquess of Blandford.

Like the rest of the 19th-century British aristocracy, the Marlboroughs regarded American women as "strange and abnormal creatures with habits and manners something between a Red Indian and a Gaiety Girl".

[6] Frances featured largely in the lives of the younger members of the family, including her grandson Winston, to whom she often acted as a substitute mother.