I think this article comes to a weird conclusion. The survey results show that mothers of overweight children are more likely to notice their daughters are overweight than their sons. The articles makes it seem like girls are healthier because of it – getting useful parental guidance on eating habits and such. It seems to me, though, that this result is just part of a larger social pressure on girls to be thin.
I’d love to see how many mothers of normal weight children perceive their kids as overweight. I bet they still perceive daughters as overweight more often than sons. The net result of this perception issue for girls is negative I think, not positive like this article seems to claim.