Advice

Im only 21 I have a one year old and im pregnant with my second my sister is so mean to my son she curses at him (I’ve told her multiple times not to) everything he does she has a problem with I always tell her he’s just a kid he doesn’t understand she yanks him by the arm and it’s just a lot I’ve told her multiple times about herself and she doesn’t care or change but yet she calls him titis baby and buys him things here and there I feel like the love is so fake and it makes me sad to see my own sister treat my son like this I was expecting her to be sooooo different this is her first nephew and I’ve cried so many times over it because I truly have no help at all and seeing how she acts towards him I’ve kept him away from her as much as possible I don’t ask her to watch him anymore because she would always make a big issue about it I’m still young I liked going out here and there but now I can’t ever again because I have no help which is fine it’s just sad because this is my sister not someone random she’s so 2 faced it’s crazy she acts like she loves him so much and treats him bad at the same time if that makes sense. Anyway what would yall do in this situation? I feel bad staying away because I love her but my son comes first. Especially now that I’m having another baby I don’t think I want her around at all tbh