Bargoo, that's funny, I can imagine it would be difficult especially if she hadn't spent enough time with the twin to be able to tell them apart! Have you seen the youtube video of a little girl meeting her dad's twin brother for the first time? Google it, it's hilarious.
DH is taking C back to the doctor today since the rash is spreading. When he talked to them on the phone yesterday they thought it might just be a heat rash and said keep an eye on it -- steroids are often used to treat rashes so it shouldn't be a reaction to the steroids. I told DH to take the toothpaste along to the doctor in case there is some ingredient in it that is common for allergies. It could also be from whatever virus caused her croup in the first place, because A doesn't have it. The croup seems about the same as before.