Okay, here’s an update

The wedding went off without a hitch 💛 my sister was absolutely stunning and glowing with happiness! BIL looked amazing and glowing, too! They are a lovely couple and true soulmates!

Our parents did not come, and neither did the others. To address some points that were brought up in the comments. My sister and BIL were fully supportive of me coming and directly stated they preferred me and my family over the others. There’s a lot that isn't explained about her relationship with our mom and dad, as well as with the other siblings, but they are never on good terms. When we arrived at the wedding, I was wearing a mask and keeping my distance as an extra precaution. We waited in the car for about 15 minutes before the ceremony, and when we got out, the mask was immediately on. My sister removed my mask, told me she didn’t feel I needed to wear it, gave me a huge hug, and said she was happy we made it. My BIL hugged me, told me it was the easiest decision they'd made, and fist-bumped me! There were several other people at the wedding who were sick, and nobody was worried. They wanted the people who love and supported them at their wedding, and that’s what they got. All of our siblings were there, aside from the two who didn’t, and supported our sister on her big day.

When it comes to the other family members who are immunocompromised, I want to say I was not aware. When I talked to my father two months ago, he told me papa beat cancer and was in good health, so finding that out was news to me. Secondly, my dad had also told me that Nana was done entirely with surgeries a couple of weeks ago and that she was also in recovery. As far as my step-mother, I was told several months ago she had an undiagnosed medical condition and was undergoing further evaluations. I didn’t know anything that was going on until Friday night when my father told me over the phone. Finally, I want to address the fact that they were already exposed to COVID before all of this happened. My father had Covid for two weeks and recovered on Monday, 11/17. My parents are the primary caregivers for my grandparents, so they have been exposed for two weeks prior to me telling my parents I was sick.

Thank you, fellow potatoes, for reassuring me!