I mean when she's what 6,7, 8, or 9 or even earlier. Or do you just say nothing about it and just let whatever happen, happen or even worst, handle it improperly throughout her adolescent life? It's quite a bit more than just talking about it once of course. Gotta' guide her along a healthy path without upsetting her, like for example having very little junk food in the house, and not making a big deal about it. Delicate operation for sure and things could go horribly wrong. Still though, I'd risk explaining to her just what's involved with . . . being fat. Would you?