Some people don't take change well, even if its vicariously. I know when I told my friends I was pregnant, several of them had bizarre reactions and I lost some of them because of that. A friend of mine basically went over the deep end when her sister announced she was pregnant, and it was all because she herself wasn't married or having kids at the time. She didn't know how to cope with it. Unfortunate, but true. Currently, I'm on my second pregnancy and one of my sister's is acting strange now. Who knows why people behave the way they do. All the comments above that suggested separation seem pretty sound to me. I know that's what I'm doing with my sister, as of today. Pregnancy is tiring and stressful enough without trying to figure out what's wrong with the next person.

Good luck to you.