This is her article in thepeerage.com, "Elizabeth Howard1 F, #177927, b. 19 January 1602/3, d. circa November 1671 Consanguinity Index=0.0%
Elizabeth Howard was born on 19 January 1602/3.5 She married John Mordaunt, 1st Earl of Peterborough, son of Henry Mordaunt, 4th Lord Mordaunt and Margaret Compton, before 7 April 1621. She died circa November 1671. She was buried on 18 November 1671.
She was the daughter of William Howard, 3rd Baron Howard of Effingham and Ann St. John. From before 7 April 1621, her married name became Mordaunt. She was a celebrated beauty, and fervent anti-monarchist.
Child of Elizabeth Howard and John Mordaunt, 1st Earl of Peterborough
John Mordaunt, 1st Viscount Mordaunt of Avalon+3 b. 18 Jun 1626, d. 5 Jun 1675."
From www.myspace.com/vladquigley 17th Century décolletage fashion.