I would not play the budgie sounds, it will get Blueberry excited thinking there are other budgies around but she will never be able to find them or interact with them. It takes a lot of time and patience to tame a budgie so do not expect miracles in a couple of weeks. It is always a good thing to have a well birdie check up with an avian vet, that way you know if the bird is healthy and it establishes you as a client and the bird as a patient, and should anything come up in the future you will already have a baseline established with a vet. The wings should cross the rump area in the back when the bird is sitting, watch her for a few days and see if they continue to droop. Regarding switching the diet to pellets, some birds will just not eat them and any diet change must be done very gradually, never remove what Blueberry is accustomed to eating and replace it with pellets thinking that if she/he is hungry they will get eaten, that will not work and you will end up starving the bird. Budgies will not eat what they do not recognize as food so unless they have been raised on pellets they do not recognize them as a food source, also be sure to offer veggies, you can start with some greens, but again Blueberry may not try them at first.
