I have a folding playpen stored right by their cage, which comes in handy. Actually, sometimes I let them stay inside their 3x6 when it's time for a total change-out. They stay at one end while I work at the other. It doesn't seem to worry them at all.
I put mine on a blanket on the couch/chair in my living room. He likes to sit there and watch tv ... if he's a little hyper that day I just put him in the bathtub like voodoo said!
I put them in their old C&C cage with some hay and a water bottle. If you have some extra crate squares, you can put about 6 or 8 of them together on the kitchen floor. It makes for easy clean up as long as you don't have carpet in your kitchen.
What do you mean by "commercial" cage? If it 2 feet by three feet that is only 6 sq. ft. of floor space which is not enough. When people talk about 2x3, 2x5 on here, they are talking about 2 grids x 5 grids, which are larger than 1 foot.
;~) Good luck with her. I give floortime while cleaning cages generally. Or my volunteer gives they grass time in a pen outdoors in nice weather.
They will be fine! I've had mine for over a year now and they still act like I'm going to eat them every time I need a cuddle. Chase them down, pick them up gently, give them an eskimo kiss and a cuddle, and do whatever you need to do. They'll get over it.