3 week old duckling with a slipped hock! Help!

[Jaggs]

I noticed yesterday that one of my ducklings was limping. I didn't worry too much about it then (kicking myself now). Today when I got a good look at her, her knee is very swollen. I did alot of online research and found that she most definately slipped a hock tendon. From the reading I did:
I massaged the area abit while extending the leg. It did slip abit back, but I don't think all the way. As soon as you relax the leg it slipped out again. So I was able to splint it in an extended position where it is the most back in. (It very may be in place but it's swollen and hard to tell). Then I created a sling for her from a tub and an old shirt with a couple holes for legs and poop. She seems content. I do have water near by with some lettuce, but no way of putting food there at the moment. I will be frequently taking her out for food and rehab.

Please.....tell me what I am missing, and what to do next. It is not in the budget to take her for surgery. If it is the only solution then she will be culled. I am trying to save her without needing it.

Thank you so much!!

The injury

The sling

I will get a picture of her leg all splinted up tomorrow. She is settled now.