Here´s my version of the CMC.
Although Babs Seed is a member of the Apple Family she is a very, very small and tiny earth-pony. One reason why the other ponys are bullying her in her home town.
Applebloom, Scootaloo and Sweetie Belle are sbout the same bodysize. Later Applebloom will become bigger than the other ones. I guess she will be a view inches smaller than Applejack.
And yes, Scootalo gave her scooter in return for a scateboard. Dunno why ...