Thanks for the suggestions, everyone.

I'm mulling it over based on what you all have said and trying to figure out what I might say next.

The funny thing about all this is I am the one who introduced her to this group of people a few months ago.

We were acquaintances, she often said we should hang out together sometime, she didn't have many friends, and so I finally asked her to come along.

I know she suffers from depression. She thinks I have depression, too. I haven't taken the next step to tell her it's actually bipolar because of little things like this rolling-the-eyes business. I don't feel like I can trust someone with my big secret if they act that way.