How is your girl otherwise? I am sorry I am unable to help more. Thinking there may be an obstruction of some kind, thus the small poops. Does she have any other symptoms? Good luck.
Vet is saying she is egg bound? This can kill her quickly, if she gets to the point that she can’t poop at all. An epsom salt bath is the first course of action, along with some calcium (oyster shell, egg shell, crushed Tums, whatever). Was this an avian vet? It concerns me if the vet indicated...