Robert Willoughby
Robert was born about 1349 in Eresby, Lincolnshire, England.  He died on August 9th, 1396 in Eresby, Lincoln, England.

 Margaret la Zouche
Margaret was born in 1352 in Northamptonshire, England.  She died at the age of 39 on October 18th, 1391 in England.

 Thomas Willoughby
Thomas was born in 1380 in Lincolnshire, England.  He died after 1400.