It's not easy to say "no, it's too soon." I sympathize, because it never seems right to deny family, but sometimes it's WRONG to welcome them prematurely. Make the best of it, you're still connected to them to a certain degree. And yes, they probably won't acknowledge the situation much because it's awkward, but it's not because they're not thinking about it or miss her. They are doing it out of respect for you, although if they really respected you, they'd hold off at least for a few months.