Elizabeth de Ros, Baroness Zouche - Elizabeth de Ros/de Roos who married William Parr

Hello -
The wife of William Parr was Elizabeth de Ros/de Roos daughter of Sir John de Roos and Katherine le Latimer. This Elizabeth did not marry a la Zouche. THAT is her cousin.
Magna Charta Shureties, 1215, 4th Ed., by Weis, p. 132.:
https://www.ancestry.com/discoveryui-content/view/62329:49232?ssrc=...

Douglas Richardson, Magna Carta Ancestry, 2nd Edition, Vol. III, p. 297 and Royal Ancestry, Vol. IV, p. 303

Thanks,
Mary