For me, it depends!
On connections, I usually marry them off as soon as the matchmaker comes. I just don't want to be late and get stuck with an oldie for too long (I'd be too lazy to raise another oldie honestly)
On color versions I might rush it if I really don't care for the character and especially if I have their tamatomos. If I like the character they might stay for a little while, though it also depends sometimes whether I want to deal with a baby or not. If I don't feel starting a new generation (as we all know, the baby stage is pretty demanding...) then I just don't.