There are several factors to take into consideration when evaluating your child's weight. Has he always been thin? Are both of his parents very thin? A child who has a genetic tendency to be thin is in a different boat than a child who has always been normal to. I'm Glad My Daughter Is Thin. byEmily Wagner Jun 13, Photograph by Getty Images. I'm hoping that once I explain where I'm coming from on this, you won't hate me for what I'm about to say. In a bid for your empathy let me first tell you that I was bullied and teased all during my youth. By the time I was in first grade I. 1 Oct Our son is thin and active, I am a long-distance runner, and my husband gets out and does what he can at the gym. We've signed her up for various rec sports over the years but she gets frustrated and has no interest in being uncomfortable. At the same time, she feels left out and left behind. I am so sad and.