drooped wing

Has anyone got any experience with a condition called 'Angel Wing'? Someone has offered me a 3 year old greenwing with this condition afflicting one of her wings and so she can't fly. After a bit of Googling, most info I found related to ducks rather than parrots. I did read somewhere that...

Her primary feathers on her left wing aren't folding away completely. They are kinda just drooping like a 'lazy wing' :( She is still being active and is able to fly and her behaviour seems normal. I initially gave her a little shower with her spray bottle incase her feathers were sticky with...