I was like this, except the pointing out people due to spots although I hated to be touched and found other people incredibly gross.
Mine started around a similiar age and turned into full blown OCD.
The guilty thoughts forced me to try to seek external reassurance and "confessing" brought me huge relief.
I confessed EVERYTHING and would cry myself to sleep over anything I thought I had done wrong.
I needed therapy (which I didn't get) or another form of help.
Because my parents didn't intervene, I am now an adult with quite severe anxiety and I struggle with agoraphobia.
I will say that my home life was very turbulent and abusive and highly religious, which is why my OCD started.
But people don't necessarily need trauma to have these struggles.
I would be making sure there hasn't been an event that has triggered this for her though.
My honest advice is PLEASE take this seriously, even if you have to find the money to get her seen privately.
My OCD ruined my teen and young adult years and I am much better now, but I do believe it all could have been avoided.
Also doing a bit of research into intrusive and impulsive thoughts may help you too.
I wish you both the very best of luck with this!