

Looking at the Overview of William de Vernon de Reviers, 5th Earl of Devon it states
"Children of William Redvers Earl of Devon and Mabirie (Mabel?) Beaumont:
Mary Redvers+
Baldwin Redvers b. a 28 Apr 1200, d. 1 Sep 1216"
Even though her birthdate is not shown showing her before Baldwin might indicate she was born first..remember this is all supposition.