Actually I am Sargood researcher. (John's 2nd wife was Anna Sargood?) The only child of John and Mary that I know of is John. He married Martha Jane King and was a hatter by trade and lived in Guernsey County, Ohio. Several of John Sr.'s kids took the name "Soverns" but for the most part the original name appears to be "Severns" I have found census with both names.
John and Anna had children: Margarite and Daniel A. Severns. Magarite appears to have never married. At the age of 39 she is living with her mother and step-father in Poweshiek County, Iowa. Daniel A. m. Harriet McCoy and ended up in Norton County, Kansas.
I have a lot more info. If you want more, let me know.