familygirl on Family Tree Circles

Using hints on ancestry.com, I have traced back to my 3rd great grandmother, Sarah Mumford Pavitt, who was born in 1799 and died in 1823 however,I cannot proceed any further as I cannot find any online records of her birth, death or marriage. Ancestry.com hints suggest that Sarah's mother was Sarah Burton (b. 1747) however, there is conflict over who was Sarah Burton's husband. ancestry.com hints present both a John Mumford (1756-1823) or a William Mumford (1737-1809). Can anyone help me to source records that may help, or share results from your own searches.
thanks Carolyn