My mom hasn't spoken to her sister since shortly after their parents died almost ten years ago. It's a long story, but basically they never had a good relationship (even as kids) and drama around my grandparents' deaths eventually led to the dissolution of their relationship entirely. I can objectively acknowledge that my aunt is not a great person, but I've kept a loose relationship with her over the years.... She lives a couple hours outside of the metropolitan city I live in, and we'll get lunch maybe once a year. I also really love her daughter even though we're not close, and in general my cousins on that side are down to earth, good people (unlike their mom who is a little nuts).
For the sake of my mom's emotions, I resolved early on just not to invite my aunt and cousins on my mom's side, but now as we're getting ready to send out the formal invitations, I'm feeling guilty about it and I don't want to completely cut myself off from these family members by offending them. My mom has reiterated that she really doesn't want her sister to be there, and I'm not close enough with my aunt to go against my mom's wishes, but is there a nice way to reach out to my aunt and cousins to sort of announce the wedding? I'm not trying to get money/gifts from them, but I'd like them to at least get the sense that I was thinking of them and still see them as family even though we don't have much overlap anymore. Or should I just not say anything and then just mention that we had a small wedding the next time I see her or my cousins (could be a year from now or more)? I never announced anything about our engagement on social media, and I don't plan to post stuff from our wedding (attention stresses me out), so there's no way they'd know without me telling them. We're also going to have about 40 people at our ceremony and 100 at our reception, so I won't feel too bad about saying we just had an intimate wedding.
What's the right way to do this?! 
