We were dying for another set of twins. We were hoping this last pregnancy would be twin girls, so we'd have two boys, two girls, and were done!! (I am not so young). This pregnancy was a girl, but just a singleton. We were both a little dissappointed (happy for the baby though, we don't get prego so easily) but in a way I felt sorry for her just being one.
DH wants six and I told him that there is no way that I will be 40 and prego and I will have one more pregnancy and if he wants six it will have to be trips.
I feel that because E is a singleton and the boys have each other, that there should be one more kiddo who knows what it's like to be a singleton. (and besides, I've always wanted 4 kids).
So yes, in short, we wanted another set.