Lady Maria Harriet Palk was born the daughter of Sir Thomas Hesketh, 5th Baronet. In 1845 she married Sir Laurence Palk (1818-1883), who was returned as M.P. for Devon South (1854-1868). He later became Baron Haldon (created 29 May 1880). The couple had four sons: Lawrence Hesketh (born in 1846), Robert Henry (born in 1848), Walter George (born abt. 1849) and Edward Arthur (born in 1854).

Baroness Haldon died on 15 December 1905, at the age of 79. The death was registered in the district of Bradfield in Berkshire.