I suppose, if you are creative, that you could make some kind of a sling out of stretchy fabric (like an old t-shirt) that had a hole for each leg and her neck. Suspend it inside a dog crate or cage? That way the weight would be off her legs. The sling would have to support her chest well...
My geese are all very bonded to each other and they never pick on each other (just the ducks) except of course for breeding season when the males get grumpy. I think that you can put "Oatmeal" outside for some quality time with her buddies without trouble.
If your birds are now on waterfowl...
Sounds like you are on the right track. Ducks and geese have very sensitive legs that are easily injured. They need more niacin then chickens so they should be fed something like Purina Flock raiser, a waterfowl starter, or a meat bird feed. Check the label to be sure that it has...