Should I call CPS?

My heart hurts for the poor babies that live upstairs. Their mom yells and cusses and is so mean to them. She talks to them like they are grown men. She goes grocery shopping then sits in the car while they carry everything up two flights of stairs by themselves. Then yells at them when they aren't fast enough. She piled trash on the balcony for a month. Eventually maggots started falling and I had to call the landlord. She got mad at the boys saying trash was their job and made them take it all down to the dumpster.. Pot smoke constantly is coming from their apartment and she has a newborn. They are probably between the ages of 4 and 6 I cant be sure. I can hear her screaming at them and they're crying. Idk if she hits them or not. I know everyone parents different but the way she talks to them is not ok. Idk it just makes me sad.