Michelle, how rude of them. I think what Sherie has said is right
Bah to them, it is their loss that they don't know your children well and this little bundle they will proably know even less. They don't know what they are missing out on.
My family was fine and happy for us when I decided to have my 3rd and 4th child. Both were planned and we were very happy to be pregnant.

DP's mother was a bit down on it when I told her that we were TTC Noah, my third and their sons first child. But we didn't care, tough to them. I think she just didn't like the fact I was making babies with her son. They have come around now. I'm not going anywhere so they really have no choice.

I think it's totally up to you how many children you have. If you want to have 10 then go for it. As long as they are well fed and looked after who's business is it!!!