I don't think I'm upset about my niece's death
Is there a reason you're not upset?
I don't know her well enough to get upset about this.
We all experience grief and the deaths of other people in our own way. If you didn't know her that well and weren't close, it's understandable that it's not impacting you as emotionally as it is others. Your reaction is not abnormal.
I'm fine with it, I didn't know the person that well anyway.
It's good that you got my point.