The Twins and Parenting

This whole book follows the life of the twins, Marion and Shiva, whose parents left them orphaned when they where born. Their mom, Sister Mary Joseph Praise, died in child birth and their dad, Thomas Paine, ran away when Sister Mary died. No one knew Sister was pregnant before she began labor and she died before they could find out who the dad was. Stone never even confesses to impregnating her and he even says he doesn't remember ever having sex with her. It is presumed that it happened when he was extremely drunk, therefore he would not remember it. It is so weird to me that everyone still accepts him as the dad when it is not certain.
When the children are born Hema decides that she is going to be the new mother of the twins, which I think is rude because she basically is brainwashing and kidnapping them. From the moment they are born she calls them "my twins" and says that she has waited her whole life to parent them. Ghosh, Hemas husband for a year, took on the responsibility of the father by going through the naming ceremony. I wonder if Hema and Ghosh will tell the twins that their real parents are dead, or if they will pretend to be the birth parents.