Why did she have her arm in a sling before being forced into the dress, something that would greatly agitate such an injury, but now that she's back she no longer has her arm in a sling? Was that a magical healing dress she was forced into? And don't tell me its the anesthetic, the entire reason you use a sling is to hold your arm in a position where you don't make an injury worse, removing the pain doesn't reduce the need for it (I've personally made that mistake).