My parents had a mixed marriage. We did not have a lot of social activities with JWs when I was young, but I think that was more about my mom than it was my dad. My JW mom isn't stupid and I don't think she wanted JWs to annoy my dad. They had a very good relationship and he adored her and she him. After he died she went into deep depression and then turned more social with JW ladies and service (she hates service but does her duty).
We did do a lot of things with our family. Some of hers were JW, none of dad's were. They had mixed groups for camping, hunting, fishing. I credit my dad for any normal childhood that I got outside of the congregation socially, but my mom was still a good mom for the most part. They did respect each others boundaries and there clearly were some, although they weren't spelled out to me. I know that at the end my dad got blood transfusions and my mom authorized them. They were never meant to save him, only to strengthen him from what I understood (cancer).
I would suggest that you encourage her to socialize outside of the org and that you even go with her sometimes. If they get hateful or condescending towards him (some will, many won't), she will be forced to go along or defend you. You being a good guy, she will have to defend you-even if internally-asking how you could be so hated by Jehovah?
My dad was the epitiome of good, decent, hardworking family man. No religion, but a good man with common sense and strong American ethics. That alone gives the JW spouse pause to consider the black/white nature of WT teachings and ideologies. My mom is still a JW, but she has admitted to me that she sees a lot of BS in the org. itself. At least it is good to know they don't have her heart and soul. I think she is just there for the socializing mostly these days, honestly. These people have been her friends for her whole life, she doesn't have any conflicting belief system and there seems to be no harm done.