Thomas de WILLOUGHBY
Thomas de was born about 1268 in Willoughby, Lincolnshire, England.  He died after 1300.

 Margaret de MUMBY
Margaret de was born in 1272 in Mumby, Spilsby, Lincolnshire, England.  Margaret de is no longer alive.

 Agnes de MUMBY
Agnes de was born about 1282 in England.