IN A GRAVEYARD in the village of Weybridge, Vt., stands an unusual headstone. It is inscribed with the names of two women, Sylvia Drake and Charity Bryant, who were born during the Revolutionary era and diedin the middle of the 19th century. The women were pillars of their community for four and a half decades, living together in a small house, running a tailoring business, teaching Sunday School, and acting as surrogate mothers and caregivers to hundreds of nieces and nephews. They were also, according to their own understanding and that of those around them, a married couple.