Mindy is expecting too, and if you have a low budget, this is how I modified my cage for the kits-
I completely blocked off the top levels of the cage so the babies don't fall and get hurt.
I bought small-spaced wire mesh (You can buy a big roll from Walmart for about 7-8 bucks..), and wrapped it around the cage (When you cut it to size, though, the ends can be INCREDIBLY sharp, so make SURE you have it where mom and kits can't cut themselves on it..) and got cardboard and put it on the flooring of the cage. I also have a shallow box of materials she can use to make a nest when she feels fit (Ripped up newspaper, hay, bedding materials, etc..). Also, I took a cardboard box and transformed it into a little house she can use once the babies get here. This would be the best way to do it, I know I really don't want to wake up one morning with a kit on the loose somewhere.
Hope I helped,
Tonya