Durham Records Online
Baptisms, Sunderland District - Record Number: 181868.0
Location: Sunderland
Church: Holy Trinity
Denomination: Anglican
22 Sep 1785 Joseph Jane Watson, daughter of William & Mary Watson, born in July last.
[Note: yes, it says Joseph Jane.]

Born 2 and a half years before her assumed parents' marriage. It's not certain that Jane is part of this family; unlike siblings William, Mary and the two Waymans whose records identify their mother as Mary Wayman, Jane's record identifies her mother only as Mary.