I may have erred about Mary (Fernald) Lovett, daughter of Amos and Abigail Fernald, unless she was recorded in 2 households in 1870, I assumed that she lived with her sister in law in 1870 with a son Fred E. Leavitt. They may be unrelated. as Mary appears with her husband Horace Lovett, in 1870 Gilford, NH with a female Nellie A. age 15. They didn't marry until 1863 so it is unlikely Fred or Nellie would be her daughter, unless She or Horace adopted them, so I can not determine their relationship to Mary, if any.
I can not find any other children for Amos Fernald and Abigail Sanborn, (they reportedly had several.) Neither can I find out about what happened to Mary Wadleigh (or Wadley)and her survivng child that she had with Amos.
These are all the clues that I can find. Perhaps someone has access to Belknap county records and can dig a bit deeper. But for now, I am at a dead end!!