How old is she again? Young kittens should never have clumping litter until they get over this stage. The cheap stuff that doesn't clump is what you need -- its CHEAP, like $2 for a HUGE bag. You use it, scoop the poop everyday and just dump it after a few days, fill the box with fresh.

Edit: just saw your other post where you said she's about 3 months. Some people say thats still too young for clumping litter. It depends on the cats, and how much of a mess they make. Try the cheap clay stuff for a bit and see if that makes a difference.