I am 20 weeks pregnant with our first baby and my best friend is throwing me a baby shower in a few months. We agreed on around 25 guests as that's about as many as her home can comfortably handle. The guest list was pretty easy to come up with - I keep a close group of a few friends and the women in my family and my husband's family are all very close. With my current guest list we are right at 25 guests.
However, about 5 months ago my husband's uncle (who we only see on the rare holiday) randomly married a woman he's been dating casually for about a year and a half. No one in the family cares for her. I personally have only met her 4 or 5 times at family dinners, and every time she's been slightly drunk, loud and rude. She's made dinners so uncomfortable that we've started to avoid attending any holidays that she'll be at.
I'm conflicted about inviting her. I don't want her there obviously- its a special time for us and our close family/friends - and I have no relationship with her. But I imagine that not inviting her will cause trouble. Even though I don't see her or interact with her regularly I don't want to cause a problem for my MIL. I love my mother in law - she's super sweet - but I know she would say the new "aunt" should be invited, only because she is very passive (I'm not) and has a hard time saying no to anyone for any reason.
Is it okay to not invite her? I feel its fair - considering I don't have a relationship with her and my guest list is at capacity - but she would be the only "member of the family" not invited. What should I say to my mother in law about it?