I am so sorry for you and this issue. Could she have gotten her head stuck in a too-small chicken wire place? And couldn't get her head unstuck without pulling and poping feather pins backward causing some bleeding. Why I say this is I do wildlife rehabbing and I have a Predator proof compound 10x10x6. Completely covered and encased in, first, regular chain link, then hand sewen on regular chicken wire. 3/4-1'' size. We have A LOT of BlueJays. Last summer we had 4 very young possums keep in the compound for acclimating back to the "wild". We had jays showing up at the feeder looking like their necks were rung. Some with signs of blood and some not but all with awful tore up fethers, just around the neck. I went to the compound to do chores and I'll be damn, there, wedged in a 1" chicken wire hole, was a huge stuck Jay. He was a mess. Had to wire cut the CW to free this very scared bird. So I started to pay closer attention to the active IN the compound. Oh my gosh, 3 jays IN THE COMPOUND. (possum food is high in protein and Jays crave protein. that's why they eat and attack little eggs and babies) I know I just go on and on. But you need to find out what possibly could have caused this. If for no other reason, to prevent it from happening again. God is helping you. Keep us update if you will. If I can't help you with my hands I can pray for help from bigger Handsokay! i will ask if we can get some! we just set up our heat lamp in the coop last night. it might have been the other girls pecking at her because she got the most heat? idk. she is usually at the top of the pecking order so this is strange to see. Thank you all for your help!