I (19F) have an older sister we will say Sarah (25F) recently haven’t been talking much bc I won’t watch my niece (2). I love both my niece and my sister but it’s gotten to the point where she never wants me to come over and hangout like we used to. The only time she ever communicates with me is when she needs help with something or she wants me to watch my niece so she can go party, like I mean only for those two reasons. If I can’t watch my niece it’s the biggest deal bc she can’t go and have fun, I work full time to make ends meet and barley have time for myself let alone constantly watch my niece.

One day I was extremely upset when she got home from drinking with her now ex boyfriend and was smoking the devils lettuce while my niece was upstairs in the room next to hers. Then proceed to tell me to never have devils tango after having neck surgery… Sarah and I don’t have that type of relationship where we talk about sex with each other, I just find it weird and awkward personally. So when I confronted her about not smoking so close to my niece she got upset with me bc it’s none of my business and it’s harmless. I know plenty of people who smoke but you do it around an infant/child especially MY niece of course I’m going to be upset. Which saying this makes me want to watch my niece more to prevent that stuff from happening more, but I’m tired of caving in and acting like when Sarah wants to party that I’ll always be the babysitter.
So AITA for ghosting my sister bc I don’t want to babysit my niece?
The Unexpected Twist: After I ghosted her, I received an unexpected text from Sarah’s ex-boyfriend. He said he knew I was upset with Sarah, and he wasn’t excusing her behavior, but he thought I should know something. He told me that Sarah has been struggling with severe postpartum depression and anxiety ever since my niece was born. She’d tried to get help, but was either dismissed or couldn’t find the right support. Her ‘partying’ and smoking… it was her way of self-medicating, a desperate attempt to escape the overwhelming feelings of despair and hopelessness. He said she was too ashamed to admit it to anyone in the family, especially after having a baby. He tried to help, but he eventually couldn’t handle the pressure, and that’s part of why they broke up.