My SO and I both have 8 year old girls. We don't currently live together. His daughter has gone through really rough times. She went over a year without seeing her mom, and now can only see her with supervised visits for 3 hours at a time. She has some pretty extreme emotional outbursts that last up to an hour.

Sometimes the girls will get along great. But I have been noticing SD is exhibiting the mean girl behaviors. Women know what I mean. SD's cousin came over and SD immediately left my daughter out of the play, manipulated her cousin into not playing with my daughter, was being extremely rotten towards my daughter. She even showed her cousin where she was hiding her toys that she didn't want my daughter playing with. This is just an example. SD will tell my daughter that SHE would look better in the clothes. She will belittle anything my daughter does. And it really gets to me.

I realize that some people assume this is normal behavior for a girl. But I think it is toxic behavior that can be changed. I think SD harbors resentment towards my daughter. I am just not 100% sure how to change that behavior. I have read articles that say girls need to learn to be more direct with anger or issues they have with each other, and manage their relationships by clearly stating why they are angry at a friend. Instead they play the mean girl games. I never did that as a child, but I was often the victim of it.

Has anyone else had an issue with this? What have you done to keep your daughters from becoming the "mean girl"?