Idk if I'm overreacting

My mother-in-law was invited to move in with us as my wife and I had our second baby in may. My MIL also has my wife's sister who is 11. My wife is 27. I'm at my wits end here months later. MIL promised to help and isn't really. She doesn't cook or clean. We watch her 11 year old and pick her up from school and take her to tutoring. 11 year old isn't awful, but she is messy and struggles in school. MIL does not pay rent, but does buy groceries. MIL does watch the baby from 8 pm to midnight maybe 2-3 times a week. It just doesn't feel like she's doing enough. Am I being too critical? Them living with us as thrown my entire family dynamic and routine off. MIL is very unpredictable and constantly rotating from being not here cause she's with a boyfriend or then showing up for a few days because they had a fight. My wife and I are having frequent fights due to the stress of her living with us and me being moody because anytime I establish a routine, it's thrown out the window because MIL decides she wants to come spend time at the house. Also, MIL asked for $10k. I stupidly said yes because I told her I didn't think she would ask me for money if it wasn't important. Turns out she bought her "dream" car, a 10 year old jeep. My wife is frustrated too. I'm just tired of fighting with my wife and then the constant unpredictability in my life. Is the few nights a week of watching the baby for a few hours worth it? Idk. Idk how to ask her to leave or what's fair.