Personal experience in my own family may give a few possible answers as to why Anthony Garrard may have named a daughter Sarah Waters Garrard, even if Sarah Waters was not his mother, or even a step-mother. My great grandfather was the 8th child of his mother Mary Elizabeth. She died 9 days after his birth, and from the time he was 15 months old he was raised by his step-mother, Rosa Isabel, who produced his next 6 siblings. My great grandfather named his oldest child and first daughter (my grandmother) after his step-mother, Rosa Isabel. He named his 2nd daughter after her godmother, Virginia Thomas, a close friend of the family, who is indeed buried beside my great grandparents. It was not until his 3rd daughter, that he used the name of his mother Mary Elizabeth. His last and 4th daughter was named for her mother, Netta Shaw, my great grandmother. I think it obvious that while names may be clues, no hard facts can be drawn from them. If Anthony Garrard named his daughter Sarah Waters, we have clues, to a number of possibilities as to the reason why, but no proof.