I don't get some people

I'm co parenting at the moment and a few weekends ago him and his mum had her on Sunday for 5 hour's and when we picked her up they told me about a lump and bruise on her head.
His mum turned to my 6 year old and said to her have you battered your baby sister to her face. I will say it wasn't there in the morning.
How can someone be so horrible to blame a kid for what they have done and they didn't own up to it. This is the 4th issue I have had with them

This page is a permanent link to the reply below and its nested replies. See all post replies »

AngelUnforgiven · 51-55, F

Deep down you should know their characters. Do you think that either of them are capable of harming her? If not, Maybe no one saw it happen and when it appeared they just assumed she'd hurt herself before leaving. In any case i wish you all the best. I know how difficult co-parenting can be. Try not to overreact, but be vigilant. Take a picture of her when she goes away with them for a few hours if you need to.