She can play BANG! cards as Missed! cards and vice versa: can she use a Punch (or any other BANG card, e.g. Knife or Buffalo Rifle) as Missed?
Vice versa, can she use an Iron plate as a Bang?
If I take, for example, Jourdonnais, he can use his ability also when he's hit by something different from the card BANG!. I'd tend to think the same is true for Calamity Janet too.