Disrespectful noisy neighbour

So we live in a flat and the neighbour below us is a nightmare. She has 2 children, the youngest child (2) screams all night all day, she wakes at 5am and starts trashing the house. The mum has put the child's play pen in the window right next to the radiator and the child smashes her toys against this constantly. When they all get up at 5am there is no consideration at all, they talk and shout so loud that I can hear every word their saying in mine, they slam doors, slam everything. I know kids are noisy, we have 3 boys but id never let them smash about and shout at 5am as I have respect for my neighbours. I've approached her about it calmly and she just said "Don't tell me how to raise my kids, if you don't like it fucking move out!"