Yelling at baby

Ni

My niece has a baby that has just turned one. And since the beginning she is a bit rough on him. Always let him cry, never picks him up in the night if he cries, she decides how much he eats even if he is crying she puts more food in his mouth if he hasn’t finished his plate. This week she started screaming at him for no reason. My mother was at my aunts place, and she was there too. She was screaming very loud and put her face right in front of his face and screaming that he need to shut up. Apparently there was really nothing that the baby did wrong.. although I think there is no reason to scream like that even if the baby did something wrong. My aunt wanted to pick him um and she told my aunt; “no, nobody is picking him up, he should just stop crying”. I don’t know, I think she has problems.. I don’t see her that much, but since we both have baby’s in the same age we text now and then. But I feel so sorry for the poor baby. I’m afraid that if she is alone with him, her behavior is even worse. What should we do? And do we need to do something? Perhaps talk with my aunt? Maybe my niece needs professional help? I hope you can give me some advice.