sentences:  At first, some of her violent acts go unnoticed; when they progress to stabbing the family dog with a needle, Jill and Rob realize something is wrong.They ask Doris, the children's caseworker, about Catherine's past, but Doris cites confidentiality laws.Following a disturbing incident when Catherine engages in sexually inappropriate behavior with her adoptive grandfather, Jill and Rob take her to a psychologist; she puts on a good show and convinces the doctor that nothing is wrong.