@chhaya, no your comment was fine(: my mom watches them while I work.

@ciaramarie311, I hope my comment didn't come off as judemental. I truly meant no offense, I'm sure you watch your kids. & if it was him, accidents happen. It's possible it could be from herself.
I'm not sure who all watches her, but if anyone other than you watches her, I'd be sure that they aren't too rough in moments of frustration. It looks more like a bruise from a finger, but she might have done it to herself. I suppose it's possible

I do @chhaya he gets in trouble when he's rough, he understands that she is little & he can really hurt her. He doesn't do it on purpose just playing but he does get in trouble when too rough. She also sucks on her hands & arms all day so I'm wondering if it could be from her doing that..

I would watch your son closely and intervene if he is too rough. it's not good for any marks to be on an infant and other people may suspect something more severe is going on.