Someone help me out 😭 badly behaved 3 year old

🪐 E.T 🪐

Basically I'm being forced to baby sit my niece every week (I'm 16). She's 3 years old and she literally drives me crazy. She curses, she hits, throws things, doesn't listen etc. I'm currently trying to babysit her but she's being so naughty and idk what I'm supposed to do. She won't tidy up any of her toys, she keeps shouting no when I ask her to do something, she threw her food on the floor, she even called me a 'little bitch'. Does anyone have any advice? Obviously it's her mother's fault that she's like this but I'm going to have to deal with this weekly 🤦‍♀️