I wasn't feeling well today so my husband took my kids to go watch SS's baseball game. My daughter was incredibly uncomfortable because BM's mother was giving her dirty looks, rolling her eyes at her, pointing and laughing and just being nasty. (The apple doesn't fall far from the tree) DH and I told my daughter that it's sad she is so incredibly insecure and unhappy with herself that she feels the need to do that to a child and isn't it great she isn't her. We just said wow.. can you imagine being that petty and insecure?
 

BM and her disgusting mother HATE my kids. I mean they are awful to them. We just keep telling my kids that people like that are incredibly unhappy with themselves and it's sad that they can't find happiness so doing that to others makes them feel better. They are bullies. That's it's not personal, it's their own issue and just to have pity on them because it takes an especially sick and desperate person to act that way towards kids. 
Any other advice on how to handle this? (Ps-my daughter is a teenager not a small child)