A parrot seemed like an obvious pick for a bird. Pretty, colourful, they can fly, perhaps even speak!
Gloria thought hard about becoming a parrot while looking at herself in the mirror. Eventually, she heard a quiet, frequent, clicking sound and then, after a few seconds of confusion, saw noticed her line of sight heading downwards. She also felt an itching sensation all over her body that eventually began to be almost painful. She looked at her arms to see the obvious blue feathers now coming in. The first species of parrot she thought about was a blue macaw and so a blue macaw she would be.
Her body continued to crackle and pop as the hard collagen in her skeleton changed shape and minimised. She started to lean forward and felt the sudden need to hold her arms to her side. Her feet had already lost two toes and grown avian scales. By the time she was about half her original height her field of view split and she noticed her newly solidified beak replacing her mouth and nose. Her beautiful plumage had now fully grown and she was almost finished. A sudden intense pain set in as the shrinking sped up and she shut her eyes, wincing as the remaining human parts of her body faded out, accompanied by the same sound as before.
Then, as soon as it had started, it was over, she opened her eyes to see her now enormous room around her. She looked down at her yellow chest, now flat. Only then, she remembered the same mirror from before and uneasily waddled over to it, her tallons tapping on the tiled floor as she went. She was just as pretty as before, if not more so. Despite lacking her feminine curves, she was still very impressed. She stretched out her left arm, now a vibrant wing and preened it with her new beak.