Is this normal?

So my LO known to get frequent diaper rashes. She using try to stretch them because it’ll hurt her. But ever since that she notice her little lady parts. I always have to hold her hands when I change her diaper if not she touch it. She starts screaming when I tell her “No. No you can’t do that.” Is this normal for babies to do. I’m concerned. I never seen any baby go that when I use take care of my nieces and nephews.