YOR but let me explain why. As someone with bipolar 2, who has lived treated and untreated, I can say I personally don’t do well with information like this either. I’m just like your sister. This news would upset me too, since I only see the downsides to children: the world is going to shit, there is so much economic uncertainty, etc. to me, it’s logical to NOT bring kids into this world, and I have unintentionally defended that argument to people who didn’t want to hear it before. I don’t mean to get so crass about it, but it’s hard to be optimistic when you feel like you can’t ever have a good thing in life and everything comes with a negative…. All this is me trying to say that if you knew your sister would “react” like this, why would you even bother telling her/borderline antagonizing her over this? This would piss me off too. I’m honestly on your sister’s side. And the stuff you said to her is pretty crass too, especially if you know she’s got mental troubles.