Ex-in-law family

I am getting divorced and trying to decide/figure out how to manage/relate to my in-laws and more importantly their extended family.  My husband recently wrote me to not contact his parents or sisters.  On the one hand I will be happy to not interact with them any more.  On the other hand we have two young daughters and they will have a lot of interaction with them.  I don’t like to have negative interactions with people or to be on bad terms, though it’s never been great with them.  I know this is a T, that of course I also believe is partly at C (maybe that is a problem).
Anyway, my husband told his sister something that made her mad at me and then maybe his whole family.  I know they all get to have their own thoughts and that him telling them could not have caused their thoughts without their consent, but I think they decided to adopt part of his thought.  At any rate, it feels very uncomfortable for me and I’m not sure if this is my awesome opportunity to release “negative people” from my life or if I need to be trying to get along with them, though that might be impossible if I am not allowed to speak with them and they do not contact me, which seems highly unlikely.
I know “negative people” is a thought and it has also come up in coaching, if someone is going to continue to do the type of actions they have done… Oh!  What was the question?  What thoughts do you want to have about it?  Feelings?  Action?  Result?
Can there actually just be people who are not that great for us to be around?  Are my only two choices to tell myself T: all the better not having contact with them or to tell myself T:  I should try to have some sort of relationship with them — and I should do most of the work in that.  Thank you!