Emily you are in control of your actions. You hold the key to what is best for your children.
Your sister is obviously very hurt from the effects of her marriage. However, as many have stated you are not your sister. It is within your power to do what is right, not what seeks revenge.
Through your posts you sound only interested in what feels good to you and letting Kevin get what he deserves. How can that be beneficial to your children? You've said over and over you wish you had two parents who loved you. Don't you think in twenty years that your girls are going to have the same desires that you are having now? This is going to sound mean but nothing gets through to you, you only hear what you want. You are being SELFISH! You need to be putting your girls first and think about what is best for them. I guess we need to keep repeating ourselves so that you get it, but too late we have been repeating ourselves!