Family Drama: Advice?

I'm just recently married. 2 months actually. Me and my husband found out the day we got back from our honeymoon that his parents were having marriage problems. Went to a very awkward dinner that night.. Couple weeks later his mom leaves his dad and 3 siblings, and moves an hour away. We found she had cheated with her partner at work. She admits to the cheating, but not it being her partner, although we have proof it was. So basically my whole first two months of marriage have been all drama and heartbreak. We planned on trying for kids right off the bat, and I'm now about 4 weeks and 3 days. I know when we tell people and she finds out she's going to want to be involved but I don't think my husband will want her to. He misses her and loves her but he's so hurt and upset because of all the lies and everything else. It's a lot of stress that I know we shouldn't be dealing with right now. Has anyone been through anything similar? Do you have any advice?