Stijntje Mulder was born 22 November 1752 in Wognum, North Holland, Netherlands to Pieter Mulder (-) and Trijntje Broers (-) and died 13 November 1818 Opmeer, North Holland, Netherlands of unspecified causes. She married Cornelis Groot (1742-1789) 8 February 1773 in Hoogwoud, North Holland, Netherlands. She married Petrus Koopman (1752-1810) 19 May 1794 in Hoogwoud, North Holland, Netherlands.
Children
| Name | Birth | Death | Joined with |
| Antje Cornelis (1774-) | |||
| Pieter Cornelisz (1775-) | |||
| Antie Cornelis (1777-) | |||
| Trijntje Groot (1779-1821) | |||
| Arie Cornelisz (1783-) | |||
| Nicolaus Cornelisz (1786-) | |||
| Adriana Cornelis (1790-) | |||
| Cornelia Groot (1790-1826) | |||
| Name | Birth | Death | Joined with |
| Maartje Koopman (1796-1797) | |||
Siblings