Does Magica De Spell's magic have any known limits that are consistently used throughout the Duckverse?

I recall some comic stating she can't produce money, but I also recall another one where she does. (I will link them when I find them). But there doesn't seem to be anything consistent where she cannot get something. (The only thing she can never do is get the Number One Dime, but even that is due to her incompetence, not to limits of her magic.)

So, is there any known, consistently adhered to, limits to Magica's magic? Or do the comic writers just make it up as they go along?