Genealogy often can be confusing, especially in families where the same names are used over and over.
It turns out that I've discovered that there were at least three Joanna Braces in that same family. There may even have been a fourth.
The Joanna married to William Pearce was not my gg grandmother, she was apparently an aunt to my gg grand mother.My gg grandmother, Joanna, also had a brother who had a daughter,(her neice), also named Joanna Brace.
It also appears that there could have been a fourth Joanna Brace in that family, but I know nothing about her.