This appears to be https://www.wikitree.com/wiki/Clare-627 seen at Wikitree as
"the daughter of Magna Carta surety baron Richard de Clare, Knt., 3rd Earl of Hertford (styled Earl of Clare) and Amice of Gloucester.[1][2] Her date and place of birth are unknown and are estimated.
She married Magna Carta surety baron Geoffrey de Say, Knt.,[2] before 1215.[1][3] They had three sons:
William, Knt., son and heir, born before 1209 (of age in 1230), died before 12 February 1271/2, married first to Sibyl ____ (said to be daughter of John Marshal) and second to Mary ____[1]
Geoffrey, was living 14 October 1246[1]
John, Knt., adult by 1242/3, married before 1242/3 to ____ de Wauton, daughter and heiress of John de Wauton[1]"
