I replied to you a little earlier before reading this post.

I'm so sorry to hear what happened to your sister.

Once my sister said to me: "you're insecure.... I'm insecure.... Our super-successful other brother is insecure... That's no coincidence, our parents messed up at some point!"

I think if someone sees their sibling go into hospital for emotional reasons that is going to have a negative impact. I would feel
1. Guilty for being stronger and
2. Afraid of reaching that point myself.

One of the first things I had to learn about myself is that, like it or not, despite actual mental problems, I'm actually quite strong (cue song "I will survive"!).