Not for feather one's in my own nest, but all mesh avatars proportions can be adjusted using some shape sliders (exemple arms and legs lenght, head size, body thickness and height, and some others). If you are tring a Demo shape, hands and feet may be enormous.
I made my yabusaka baby smaller and chubbier, and my toddleedoo Kid close to Baby height.
Also remember that all Tiny avatars uses reducer (mesh avatars too), justbe sure when you try them to relog after you worn everything or you may look deformed.