In 1722, Melusina was created Baroness Aldborough and Countess of Walsingham as a life peer. After the death of her father in 1727, she lived mainly with her mother at
Kendal House in
Isleworth. In
Isleworth, Middlesex, on 5 September 1733 Melusina married
Philip Stanhope, 4th Earl of Chesterfield, a leading
Whig politician. The couple had no children, but it is said that "family letters" suggest that Melusina may have been the mother, through an intimacy with
Charles Calvert, 5th Baron Baltimore, of
Benedict Swingate Calvert. Calvert was born in England in around 1730–32, the illegitimate son of the 5th Baron Baltimore, while his mother's identity is otherwise unknown. ==References==