Looking for Info on Sarah Piggot Who Married Ton Pearce IN 1877

I am trying to trace the ancestors of my Great Grandmother (Sarah Piggot) whose mother it is rumoured in the family was Leonora Stackpoole who married a British army Captain Piggot. I can find no trace of them in English records but we do have some lovely stories about Leonora being dandled on the knee of Victor Hugo in Guernsay amongst other tales.