Charlotte Julia Campbell, Countess of Rothes attributed to Richard Cosway (Clan Leslie Charitable Trust)
The collection that includes this is probably at Leslie House, in Leslie, Fife.
This is her terse article from thepeerage, "Charlotte Julia Campbell F, #19029, d. 21 May 1846
Charlotte Julia Campbell was the daughter of Colonel John Campbell. She married George William Glanville, 13th Earl of Rothes, son of George Raymond Evelyn-Glanville and Jane Elizabeth Leslie, Countess of Rothes, in 1798. She died on 21 May 1846.
Her married name became Glanville."