Theodosia was a Quaker. I've found several mentions of her in Quaker Meeting Records on ancestry.com. I haven't found a marriage record, but she married Henry Rulon, son of David Rulon and Exercise Allen, prior to the birth of their first child in 1758. She gave birth to ten children, 9 boys and 1 girl: John (b. 1758, my 4th great grandfather and the father of Sarah Rulon), Benjamin (b. 1761), David (b. 1763), Nathaniel (b. 1764), Moses (b. 1767), Henry (b. 1769), Jonathan (b. 1774), Abel (b. 1779), Anna (b. 1782), and Ephraim (b. 1784).
It looks like Theodosia and Henry and their family lived in Cumberland County, New Jersey. Henry is listed in several tax lists in that county. Henry died on February 8, 1810, in Cumberland. Theodosia out-lived him by 15 years and died on February 26, 1825.
|Cumberland County, New Jersey, as of 1758 where Theodosia Robbins and Henry Rulon lived (from http://www.randymajors.com/p/maps.html)|
This post is part of the 52 Ancestors in 52 Weeks challenge by genealogist Amy Crow at No Story Too Small.
 Ancestry.com U. S. Quaker Meeting Records, 1681-1994, Green Street Monthly Meeting, Philadelphia, Pennsylvania, Births 1728-1884, Deaths 1798-1885, birth record for Theodosia Robbins; Ancestry.com. New Jersey Marriage Records 1683-1802, for Nathaniel Robins and Ruth Vanroom; Ancestry.com, Bible record for Nathaniel and Ruth Robbins, from the GSNJ Bible Collection #4364, added by SaraHoffman505.