I know that you posted this years ago, but was hoping for an update. My daughter is 4 and is doing this exact same thing.
Thank you for your comments. She really hasn't been around anyone like that but we did put our house up for sale and she is graduating from kindergarten. She says this stuff doesn't bother her and she acts excited. I do think it may play a part, though.
Has she had any significant changes in her life that the others did not? An overly sensitive babysitter or sibling. I know I have one relative that whenever I am around her too much I start overly apologizing this might be a similar situation? .
I think that I'd keep my eye on her and make sure she isn't ruminating on thoughts which would be a sign of some anxiety. But I think it sounds like you have a super kid that is very insightful. I guess you could say that you wish she didn't look judgementally to others and it is a little young for that. But . . . she realizes that she doesn't want to hurt others. So go with reassuring her that we all have thoughts that we just don't share.
good luck