Joan FitzWilliam

- Aft 22 Dec 1347 (1300–1384)

Parents

• Isabel Deincourt
• Sir William FitzWilliam, of Elmley and Sprotborough

Children

• Margaret Thornhill
• Simon Thornhill
• Elizabeth Thornhill

Siblings

• Sir John FitzWilliam, of Elmley and Sprotborough
• Margaret FitzWilliam