Hey ferret owners! Please read!?

I have a ferret who is a kit. I have had her for a few months now, and she is very rambunctious, which is expected. But I am not sure if the cage I have is big enough for her. It is a "super pet" cage with a ground level, middle level and top level. Whenever I am home she is out of her cage, but the times when I am not home, I want her to be able to have enough room to play in or whatever. So my question is, what cages do you guys use? What cages do you think would be more suitable for her? Or am I being silly and the cage she has now is good enough? Help me!