Some bird of prey geek info for ya...........they are cliff nesters, laying about 6 eggs at a time. They are the only owl known to soar in the daytime. They are huge, but not the largest owl species, and can hunt and kill prey as large as young deer.
Owls are known to be aggressive in captivity, so this is a rare find indeed. From the looks of her feet, she has been in captivity for awhile, meaning she was either captive raised or captured/rehabbed young.
In this video, she is being trained to fly to a lure, so it is possible that this is a rehab girl and is being prepared for release!
Good find, Queen Mum. Thanks for sharing. It's good to see one as well cared for as she was.