That much gold every five minutes in Fable 2 actually would be absurd. That much in an hour of play, however, or all at once after having not played for a while? No problem.
I wasn't originally sure how I was going to explain away not being able to just physically give frozen enemies potions, but slow time acting more like it actually should is pretty much all that's needed, really. It's possible she could manage it with them just moving a bit more slowly, but not reliably, I wouldn't think.
Granted, she could just throw the potions at them, but SSSSH! My logic is FLAWLESS!