Let me start by saying this is a very long story in the middle of legal issues, so some of the details will be left out for privacy.
My sister is my bridesmaid and she is in the middle of some very serious marriage issues. About two months ago she left her husband on a trial separation basis, filed divorce papers and has since considered reconciling in the best interest of their children (it's a huge ugly complicated mess, so while it may appear as though she's making rash decisions in a short amount of time, it's been very difficult for everyone involved.)
The reasons for why she chose to separate from her husband have caused my family to want nothing to do with him - he's not welcome in our lives. If she decides to go back to him, that's her own business, but he won't be part of our lives.
My wedding is in about 4 months and I am filled with anxiety over this. My sister has been known to go off the grid if she feels like she's being slighted. I know she wants more than anything for her marriage to work, but how should I proceed?