I think that's great, that your lil girl is feeling that secure.
I pondered long and hard on how to answer "why". I think, maybe, they get a little security from getting some sort of answer; from hearing us say we know why and everything's still OK. Make sense?
I tell my lil one that her mom and I just get along much better apart; we both still love her and will make sure she's always ok, but we can do that and many other things better apart. She seems to accept that, because even 5 y.o.s see that sometimes people just don't get along. That's my $.02.
