It’s driving me mad! The only thing I can remember is a young boy and his older sister are at their babysitters house. Babysitter who is a middle aged woman is distracted by phone/tv/something and the little boy falls in the pool. He’s fished out (possibly a dog is involved?) and is fine, the older sister (11ish?) calls mum and mum comes raging at the babysitter and drags kids away which sets the scene for the premise of the movie which is ....... I can’t remember!!
The setting is those one story homes with large front lawns out door pools and space between houses, somewhere hot in America, California/Texas/Arizona.
Ring any bells with anyone?
(It’s entirely possible it was a TV episode, but I think it was a film)