honor wardrobe requests if they happen to have the type of outfit you are asking for. If they do not have it, she might tell you if you will buy it, she will wear it. In either case, you just have to ask.
Hope your procedure has a good result, and you can soon resume your sinful ways, my friend. Happy she was understanding, but would assume most would be if you are honest about your situation for having to cancel. Hopefully, if she was someone you really want to see that you can re-schedule.