Who are Ann and Thomas Putnam in The Crucible? What do they suggest is Betty's problem?What is their motivation for suggesting this?

Ann and Thomas Putnam have buried all their babies but Ruth. Ann believes that something sinister surrounds their life , because now their only surviving child is under some type of spell. It is much easier for them to believe that some force out of their control is to blame for their woes. Witchcraft makes them blameless.