Here's my thing: it's your call, no one else's. You are probably going to have family members see both sides and some may judge/offer their opinion on whether you should have gone or not but they wouldn't be home with DD when she did contract the PE. To me, idc who judges me on overreacting or not, if you don't want to take the chance then I wouldn't go no matter who had anything to say about it.
If it's worth it to you to stay home rather than taking the chance to hang out then I'd stay home. Now, if it were my situation swapping the RSV with the PE risk, I'd go but that's because (to me) it is important for us to get together with the whole family (since it doesn't happen too often - out of towners) and I am a SAHM so I could take care of Sof if she got it. To me, the RSV thing is scarier because of what I've read and what I am unsure of so that's why I am debating about going to ours or not.
Pink eye - I'd risk it if it's a week away and you really wanted to go, but if DD has been having a hard time lately and it's not worth the risk, I'd stay home.