Probably-posthumous daughter of Sir William de Clare; poorly attested (Burke's Peerage is not infallible). Identity of her mother is not certain; Margery de Burgh was married to Theobald le Boteler c. 1240-1248, and she did pay a fine to remarry in 1250, but there is no record of whom, or if, she took for a second husband.

Isabel de Clare married Ralph de la Rochelle.2,3 Family

• Ralph de la Rochelle Child
• Anne de la Rochelle+2,3

References

• http://our-royal-titled-noble-and-commoner-ancestors.com/p433.htm#i...

1. Unknown author, The Complete Peerage, by Cokayne, Vol. VI, p. 175.
2. [S16] Douglas Richardson, Magna Carta Ancestry, 2nd Edition, Vol. IV, p. 343. GoogleBooks
3. Douglas Richardson, Royal Ancestry, Vol. V, p. 369.