Not exactly a book suggestion...(although, looking at it from the opposite end of the spectrum, my 7 year old is the size of an average 8/9 year old and taller than small 10 year olds)...MOST kids books have the protagonist as "little". From very young kid's books, like the little engine that could, to the Berenstain Bears, to myriad pictureboks like Chopsticks, or chapter books -the Stilton, Mouse dective...the Littles...Stuart Little, etc- where the main character is a MOUSE, and by definition littler than EVERYONE. Let's also not forget Lucy in the Lion Witch & the Wardrobe, or twins in Spiderwick, or Harry Potter, or Jack & Annie in the Magic Treehouse, or Charlie in Charlie & the Chocolate factory, or Madeline who littler than everyone else (and pluckier)...actually that's a BIG theme...Little & Plucky. In Most children's books, the small characters are the heros and the tall children are the bullies. Although in my own personal experience ;), it tends to be the littler kids who are bullies...whether it's Napoleon-esque, or just never being taught to be carefull of bigger kids. That sounds odd, doesn't it? But it physicially hurts to get hit/kicked/punched as WELL as hurts bigger kids feelings...yet for some reason parents with littler kids seem to think it's okay for their smaller one to beat up on my bigger one. Nope.).
Oops...side tracked...
Anyhow...not exactly a book suggestion...but speaking from an athlete's point of view...it's better to be smaller than average for MOST sports. Dance, gymnastics, horse racing, diving, ice skating, crew, martial arts, soccer, climbing, skiing, snowboarding, skating boarding, surfing, gosh...the list could just go on and on. It has to deal with
- being able to have the rotation necessary to be competitive
- lower center of gravity
- better body control younger (taller kids have more growth spurts, which then means they have to start all over learning muscle memory)...these are things like coordination, balance, coiled power, rotation, body awareness, etc.
- better strength to weight ratio (similar as above...if you're 70 pounds it's harder for little biceps to pull you up than if you're 40 pounds. Since muscles have a limited amount of development that they can do before puberty, and then after puberty if you're STILL growing and growing...essentially it gives littler kids about a 10 year head start on their strength to weight AND body control).
<grinning> Anyhow...this list could also go on...good luck!