You can try syringe feeding her small amounts of pureed layer crumble/pellet, but she will need to get many many small meals this way to get enough calories. Another way would be to get someone to teach you how to tube (crop) feed her- this is passing a soft tube into her crop from her beak- and filling up her crop 3-4 times a day. This way will get more calories into her in shorter amount of time. A vet visit can get this info/tools/demo, or if you do not have this option, if you can find someone who breeds parrots nearby- most of these folks know how to crop feed (gavage). It sounds hard, but with a small amount of practice- is relatively easy to do.