fell out with my sister in law over kids sister in law from hell

I have fell out with my sister in law over the kids. I have 5 and 7 year old boys. She has a 3 year old boy and 6 month old girl.

She watches my boys like a hawk when we are all together and acts like her boy is breakable. She really picks on everything my youngest does and eyeballs him all the time. I had noticed it on several occassions but let it drop. She accused my son of lying when she asked him why her son was crying. when she didnt see what had happened before it.

The final straw came when at a family do she totally eyeballed my son non stop, constantly said be careful, watch him, dont do that etc. Placed her 6 month baby on the floor for a kick around in a very small lounge and then told my son off when a car got flung of the toy garage onto the floor by the baby. He must have been so concious of her at him that he absolutley broke his heart crying.

When we left i was ranting and raving to my husband who most of the time takes not a lot of notice until . . . The next day my other sister in law told me that when we had gone. She was talking about my son with her dad (grandad) saying he was rough as usual etc.. I just feel like she has been slagging off my family. My husband had a word with his dad about it and i think the dad has told her i was unhappy with the situation. By the way her son is no angel. He has made my son cry and also hit my older son. My son is no angel either but he certainly isnt as bad as she makes out. I have my other sister in law and my brother in law to back me up so im not being blinkered to what my son is.

The point is we have not spoken since. We have texted politely but thats it. I called her to invite her son to my sons party but got her husband. She has not called me back.

What shall i do when we next meet at a family do? Should i let my kids play with her precious son or keep them away if it is going to cause trouble.

Sorry for my rambling post and thanks for listening.