So you 'stick em' ... is that what your saying???"Could" is a pretty nebulous term and a tall order. I've been doing venipuncture for over 30 yrs and don't think I could tell a ring size from a photo--and could not tell a size 4 from a 4.25 or even a size 5.
Unless someone comes forth with the ring size of both girls and one size is that much bigger/smaller than the other, that "could" becomes an even taller order. JMO
The ring size itself is not so much the issue, IMO. The shape of the hands, fingers, knuckles, nailbeds, nailshape and vasculature will be telling enough as both girls have very distinct hands.
But again, dissecting the anatomy(which we've done many, many seasons) becomes a moot issue if TPTB do not give us an FRC scs to dissect.