While I substantially agree with this post, I have to say that sensitivity is a two-way street. The one who are not yet married, have children, good jobs, etc. have to also be sensitive to the fact that walking on eggshells around you, makes these get-togethers very uncomfortable and awkward for the person who has to refrain from showing excitement that their baby has just reacjhed a major milestone (because someone there has no children),or that the wedding plans have come together (when someone else is not yet married). Both sides needs to act and speak with sensitivity to each other.
My children had a very tough time conceiving, and had a miscarriage when they finally did, after several years. At the same time that this happened, my friend became a grandmother. Should I have stayed away from the bris or not allowed her to express her joy to me, ebcause I was sad about our situation? That is selfish, I am sorry to say. I trylu believe that when we show Hashem we are genuinely happy for someone else’s simcha, He looks to increase our own simcha.
So don’t go overboard,everyone be sensitive in both ways to everyone, and try to not take these things personally. I kow it’s harder some times than others, but family get togethers will ALWAYS be what they are. If it is too painful, stay away. Honestly.