The Guardian (1990)

Optimistic about their future, well-off parents Kate (Carey Lowell) and Phil (Dwier Brown) hire the pleasant and lovely young Camilla (Jenny Seagrove) to live with them and care for their new baby. Though Camilla seems like an answer to their prayers, she proves to be more than she appears, and a diabolical plot involving the wellbeing of their child is uncovered. The young parents are forced to fight supernatural forces for the life of their vulnerable offspring.