what size clothing do the realborns wear that have just been released in the last several months that are between 17-21"
Newborn, 21 inch may fit 0-3
Newborn size for most
My Miya turned out pretty tiny, for onesies and such newborn is usually too big, a preemie size fits better.
I have found that preemie size fits 17-18 inch babies, 19-20 fits newborns and 0-3 months fits 21-22 inch babies.