Research Notes:
John Fitz-Herbert, Lord of Norbury, reportedly married Agnes, daughter and heiress of Osbert de Stretton, of Etwall, Derbyshire, and had son John. [1]
[1] Charles Mosley, ed., Burke's Peerage, Baronetage, & Knightage, 107th edition, Vol. 3 (Willington, Delaware: Burke's Peerage & Gentry, LLC, 2003), 3710.