You can try wrapping the wing close to its body although the older they get the wrap won't work because the cartilage is not as soft.The ducks are around 11 weeks- got them on Halloween ( day old) - I noticed the wing about a week or so ago
Getting good pictures is hard , I hung out in their coop for awhile trying to get pics and every time I raised the camera they flocked to the other side. I got the ones above by taking pictures outside the coop and zooming in.