Firstly, I don’t believe your kids should be with her for a week over summer.

I know you say that not seeing her at all is not going to happen.

Maybe you can write her a letter so that you can think about your words first. Give HER the choice to change her ways when you come to visit and tell her that unless she treats you and the kids different then you won’t be coming around.

If she threatens suicide tell her that you will block all contact with her until she stops saying that. She is very manipulative and you and your kids do not deserve it