Lady Gosford was the third of five children born to Countess Louisa van Alten by her first husband, William Montagu, 7th Duke of Manchester.
[1] Her older brother, George, became the 8th Duke of Manchester and married Cuban-American heiress Consuelo Yznaga.
Mildred Cecilia Harriet Stuart, daughter of Henry Sturt, 1st Baron Alington), and Lady Alice Maude Olivia Montagu (wife of Edward Stanley, 17th Earl of Derby).
[2] On 10 August 1876, Lady Louisa was married to Archibald Acheson, 4th Earl of Gosford in Market Hill, County Armagh, Ireland.
Together, they were the parents of:[3] From 1901 to 1925, she served as a Lady of the Bedchamber to Queen Alexandra, the wife of King Edward VII.