Isabel de Bolebec [the younger]

  Research Notes:

From Wikipedia - Isabel de Bolebec:
Her niece bore the same first and surname, Isabel de Bolebec [daughter of Hugh II de Bolebec and wife of Robert de Vere], and also married a de Vere, Robert's brother Aubrey de Vere, 2nd earl of Oxford . That has led to confusion and difficulty separating the two women. Isabel the younger had died by 1207, and her aunts Isabel and Constance were her co-heirs.

Isabel married Aubrey IV de Vere 2nd Earl of Oxford, son of Aubrey III de Vere 1st Earl of Oxford and Count of Guînes and Agnes of Essex, before 1207. (Aubrey IV de Vere 2nd Earl of Oxford was born before 1164 and died in Oct 1214.)