I've started looking at this family too. Ann and her granddaughter Margaret Elizabeth were buried in a plot owned by my ancestor Orrin Briggs. I am wondering what the relationship (if any) was between the families.... when Ann was buried in 1859, Orrin had moved on. He was in Wisconsin, then Missouri. After 1860 he was in Iowa.
Orrin had a first wife, possibly named Mary. Did you also find the ship records for the Gomer arriving in New York in 1827? From that list (if it's the same family), Richard and Ann had a daughter named Mary, born approx 1811.
If you can shed any light, get in touch. If I find out anything else, I'll post it here. Thanks, Lisa