I hope this may help. I'm not sure that Edward ever married Amy as he would have had to divorce her to marry Marcy. Now, I have a death date for Marcy of 1745 which meant Edward remarried to Esther in 1745. That would make her John's mother.
Mourning of only 90 days was allowed back in that time. Things had to move on and families needed all the aid they could get.
My research would make Prudence and Stephen are Marcy's. The rest of the children are Esther's. I have a total of 13.