Biological family drama

When my mom was young her bio mom walked out from what I've been told. Grandpa met and married my nana who raised my mom almost 40 years ago. I met bio grandma when I was 18. We've talked a few times in the past 10 years. My mom just got married and invited bio mom, nana got upset, felt betrayed. Questions about my wedding came up, naturally.

Now nana is freaking out and won't talk to me because she doesn't want me inviting bio grandma to my wedding. I have two uncles who I would like to invite who are close to bio grandma and it's an "all or none" for me because I'd feel terrible and bio would find out.

I feel trapped and just want to cancel my wedding entirely and just elope. How did their adult issues become my problem 3 generations and 45 years later? 😢😭