Injured finch--help?

[Flight Feathers]

Thanx. My yard is full of bird feeders & every so often one flies into a window, but this looks like a different kind of injury. Otherwise the bird seems healthy. I just worry that I'm doing her more harm than good if I'm stressing her by keeping her in a box. I could just leave her to her fate and let her"rejoin the food chain" but I hate doing that.

Keep it in a box for the first day/night and then move it to a small bird cage that isn't very tall