Aww pup-pups! How exciting!!!
The standard for Belgians and GSDs is actually the same height wise 22-24" for girls and 24-26" for boys. It's just GSDs tend to be a bit heavier than comparatively sized Belgians because they tend to be heavier boned and longer bodied. And many, many GSDs are oversized, either too tall and/or too heavy boned. Although Knox and my boy Belgian are about the same height/weight.
Elsie and Whimsy are the same size