Do these look like pinch marks?

Je
So my husband and I are temporarily staying with his dad, stepmom, and little sister. Yesterday no one was here except me him and his sister who is 9. We asked her to hold our daughter for a minute (she's 6 months) and left the room to clean some stuff up. Well we heard eris, our daughter, start crying so my husband went to check on her and she had 2 very deep purple and red marks that look like pinch marks on her leg! These pictures were taken a couple hours later. Well he left to go to his stepmoms work to tell her and she didn't believe him! When she got home later she looked at eris and still didn't believe us. She said "oh well she could have picked her up wrong". But that wouldn't have left marks like this and it's 24 hours later and the marks are still there and one is bruised. And his little sister just said she didn't know what happened and it wasn't her. But lately she's been acting out by lying and stealing. I'm just so mad cause I know she's 9 but she's held her many times without any problems which is why we trusted her. We even explored other options like his sister said it could have been legos, the cats, her bracelet, etc. Sorry this is so long but I'm just very frustrated with the situation.