This is her brief article in thepeerage,com, "Hon. Margaret Brooke
F, #11836, b. 1642, d. 6 January 1666/67
Hon. Margaret Brooke was born in 1642.3 She married Sir John Denham on 25 May 1665.1 She died on 6 January 1666/67, without issue.
She was the daughter of Sir William Brooke and Penelope Hill. She was for a short time the acknowledged mistress of the Duke of York (later King James II). She and James II Stuart, King of Great Britain were associated. On 19 May 1665 she was granted the precedence of a daughter of a Baron. From 25 May 1665, her married name became Denham."