| Father | John Beaufort 1st Earl of Somerset (1373 - 1410) |
| Mother | Lady Margaret Holland Duchess of Clarence (1385 - 1439) |
| Sibling | Edmund Beaufort 2nd Duke of Somerset (1406 - 1455) |
| Sibling | Henry Beaufort 2nd Earl of Somerset (1401 - 1418) |
| Sibling | Jane Beaufort (1402 - 1440) |
| Sibling | John Beaufort (1403 - 1444) |
| Sibling | John Beaufort 1st Duke of Somerset (1404 - 1444) |
| Sibling | Thomas Beaufort Count of Perche (1405 - 1431) |
| Sibling | Joan Beaufort Queen Consort of Scotland (1407 - 1445) |
| Sibling | Margaret Beaufort (1408 - 1449) |
| Sibling | Elizabeth Lancaster (1408 - 1475) |