AITAH if I cut my sister in law off:

Okay so, honestly I don’t know where to start since this is a pretty personal story but I genuinely don’t know what to do. So I lived with my mom for majority of my life until I was 15 then one thing lead to another and I was left at the airport. I decided then that I didn’t want to live with her anymore. So I started living dad and stayed at my brother’s. At the time he had his wife ofc let’s call her Tiffany and his son. I will admit when I first started living there I didn’t know much about the basics like cleaning, washing dishes etc… which was expected of me to do as soon as I got there. Fast forward she got pregnant and based off her past it was high risk so everyone knew to be careful, I got sick one day after going out to eat with my dad and I was throwing up and in laymen’s term releasing from the other side as well. Honestly I didn’t know what was wrong but still told Tiffany from upstairs that “hey I don’t feel good, what do you want me to do?” She told me that it’s better if I went over to my other brother’s house, granted it wasn’t far at all but it was like 11 at night during the winter. But honestly I wasn’t mad about it she’s pregnant and it’s high risk that says it all. I called my dad he took me to the hospital and it just turned out to be food poisoning,also I should mention this was during the wrap up of Covid so in my eyes she’s was complete justified. However, what really changed my mind was the treatment I received for helping her after she had given birth to the baby. I helped in the summer watching the baby in the morning, cleaning after words, then watching shows with her because I know that postpartum is a thing. This got draining fast I mean I was only 17 at the time, and she would turn around and tell my older brother I didn’t do anything around the house. After this I decided I was done and no longer stayed at Tiffany’s house I started living at my other brothers who I mentioned at the beginning. What really has me asking this question however is because I recently visited back there for winter break( mainly because they kick us out of the dorms during winter) and my other brother that I stayed with was out on vacation so I asked if I could stay at their house for just 2 days. Mind you when I got on the train I was feeling totally fine, but I’m a person that gets sick really easily, they picked me up from the train station and it seem my nephew had gotten sick from school. So the next morning I woke up feeling sick as well, she came into the room saw that I was sick and told me that it’s better I stay over at my brothers house who were not there, because she didn’t want her kids to catch it. Mind you I caught it from her kids, anyways I left like before. When I got in the house it was freezing and the heater couldn’t be turned on until my brother got back so I stayed in the cold house until they got back to turn it on. I have to go back for the summer and thinking back on it I don’t know how I should act towards her, I don’t plan on staying at her house for sure but I’ll still have to see her. What should I do?