Beautiful Barn Owl ! I would love to be able to have one, you are so lucky to get to keep her. In the past I have cared for Boobook owls and Tawny Frogmouths (Tawny's are actaully a nightjar), but a Barn Owl would be amazing. So she doesn't get any mice, rats or large locust type insects?
I guess she knows the good things in live , our cat refuses to catch sparrows (a huge pest over here) they must taste horrible, but let you be cutting up some raw chicken and the cat is a demanding bansehee. At work (my local zoo) there is a Tawny frogmouth that flat refuses to eat any mice that aren't white .