Richard II Seymour de St. Maur
Richard II Seymour de was born before 1385.  He died after 1409.

 Mary Peyvre
She died after 1409.

 Alice Seymour de St. Maur
Alice Seymour de was born on July 24th, 1409.  She died after 1431 in Harringworth, Northamptonshire, England.