What do you think about this comment on my character?

I’m in a very small private FB art group. The group only has a few members and they are all people I know in real life, and no one outside of the group can see the group’s activities. The idea of the group is that we would post our random works of art in one place so that we don’t have to do that on our messaging app. It’s just a friendly place to share random arts between friends.

So I posted some sketches of the Continental Army captain of my story on the group. Accompanied the art was a short basic introduction of the captain’s situation and personality. I wrote that he is depressed and plagued with guilt for executing his best friend. Then under the comment someone wrote “depression haha”. I asked why she laughed at the guy’s depression, and she answered that she commented like that because she has it worse than the guy.

I know that person in real life, and I can confirm that she struggles with some mental disorder that kind of hampers her daily life. I can’t disclose the disorder for personal reasons. But her comment was really jarring to me. I don’t know what to think of it. On one hand she does struggle from mental problems, and besides this is just a fictional character, so I don’t think it’s worth it to fixate on the matter. But on the other hand, I fail to see the joke here. I’m utterly baffled at how the captain’s depression could be funny to her.

What do you think about the comment?