| Father | Sir Thomas Cornwallis "High Sheriff of Norfolk And Suffolk, Privy Councillor, Treasurer of Calais, Comptroller of The Household, Elected Mp" (1519 - 1604) |
| Mother | Anne Jerningham "Lady of The Privy Chamber To Queen Mary" (1516 - 1581) |
| Sibling | Elizabeth Cornwallis (1549 - 1628) |
| Sibling | Ann Cornwallis (1551 - 1603) |
| Sibling | Alice Cornwallis (1552 - ) |
| Sibling | Mary Cornwallis (1551 - ) |
| Sibling | Hannah Cornwallis (1553 - ) |
| Sibling | Ruth Cornwallis (1555 - ) |
| Sibling | Sir William Cornwallis Knight (1547 - 1611) |
| Sibling | Alice Cornwallis (1552 - ) |
| Sibling | John Cornwallis (1547 - ) |
| Sibling | Sir Charles Cornwallis Mp (1542 - 1629) |