William de Vernon de Reviers , Earl of Devon 6th
William de Vernon was born in 1128 in Devonshire, England.  He died at the age of 89 on September 8th, 1217.

 Mabel de Beaumont
Mabel was born about 1168 in Meulan, Normandy, France.  Mabel is no longer alive.

 Mary de Reviers
Mary was born in 1196 in Okehampton, Devonshire, England.