Question: When was Dorothy Percy, Countess Of Northumberland's mother born?
Sentence (from "Dorothy Percy, Countess of Northumberland"): Dorothy Percy (née Devereux), Countess of Northumberland (formerly Perrot, née Devereux; c. 1564 – 3 August 1619) was the younger daughter of Walter Devereux, 1st Earl of Essex by Lettice Knollys, and the wife of Henry Percy, 9th Earl of Northumberland.
Relevant evidence: Yes