Sibling advice jealousy

I'm looking for some help. I have only one sibling we grew up so close and even lived together as adults. Now we each have our own families and things went rocky from the start there. As soon as we got married it was like they were in competition with us. At one point after the passing of one of our parents I thought we could be closer but the sibling just kept lashing out at me over their life. They would say things like "I don't have a marriage like yours."

When it came to children we were shocked but everyone of their biological children are severely autistic none verbal. My children are not. Therefore family started telling me they didn't want to be around us. They ignored my kids at different times. Even as a godparent to my eldest. I've been told they are jealous and can't stand to be around us. It breaks my heart as we love them.

Now they are getting a divorce. My heart is broken for them. They really don't want to be around us as I'm being told it's too painful for them. Christmas we plan on going to my only living parent's home. I'm so worried this sibling will lash out at me or cause strife for my parent with their attitude. What can I do? Again I am trying to understand their feelings but this has been going on for over six years now and I'm losing patience being treated terrible for my average life. We all have our own challenges and I don't project anger at them for my life.