Birds in stressful or neglected situations sometimes 'over preen' by pulling out their feathers. She is now living at the Tallgrass Parrot Sanctuary.
It's a little cool to be featherless so some thoughtful soul came up with a sweater for her. I think it's likely she will never have full plumage again. Only time will tell.
Every girl needs a Christmas sweater. The ring on her leg indicates she hatched in 1996.
I've taken these photos from Facebook and Instagram. You will find her story interesting.