Stress/anxiety

Amna

I have a 5 year old and baby2 on the way. I am staying at my mom's house for four days. Husband is on business tour. My sister also lives with at my moms house with her two kids 2.5 year old and 1 year old. I'm just having lots of stress and anxiety feeling as my sisters 2.5 year old girl is constantly bullying my 5 year old girl. She hits her, throws tantrums every time my daughter touches anything in the house. Laundry,chair,cushions. I already told my daughter not to touch her cousins toys and she doesnt. But 2.5year old just reacts to everything. It's getting too annoying! I already spoke to my sister and she is also very worried about this habbit of her daughter and tries her best to properly discipline.

My question here is, all this silly stress is not harming my baby2 right? I read stuff online that it effects baby brain. Am I thinking wayyyyy too much?