You want to be so happy but.....

Me and my husband are so happy that we are expecting our first, so are our parents it's the first grandchild for all, my problem is that my brother and sister in law have been trying for over 2 years, it's difficult coz he works on and off at sea but there struggling, so when I told I was expecting, the response I got was 'that was quick' she went home and cried and wouldn't speak to me for a week, I want to enjoy this moment but can't help but feel bad. Anyone else experiencing this?