My research is in its beginning stages but I did find that Edward was married to Rachel Silver from Maryland and they had a lot of children. He and Rachel were together on every census I can find, the last being 1870 and they lived with one of their sons. Dolly's four children were born within the same years Rachel's were. One born 1812, one born 1813... you get the idea.
So now new questions, IS Edward the father to any of the Briggs children? Was Dolly so in love with him that she accepted him as is as "life partner" seems to imply? Did Dolly live fully devoted to him and spurn any other mans attentions? She must have known about Rachel, did Rachel know about her? Did he love them both, did he love either? And all those children.... if all of them are his, he was a viril man and it does put his nickname of "Big Ned" in a different perspective? I know, I digress, don't groan so loudly. :)
When I first started looking into him via ancestry.com I thought maybe Dolly had come with him and his family from South Carolina to North Carolina. Were they just age old friends?
It looks to be an interesting story but I find myself at a cross roads until I find something that maybe explains their relationship. At this point I don't think I can assume he was Mary Jane's father. I wonder what life was like for the Briggs children...