Fleas on Nursing Cats and Kittens

Question
My cat is nursing 2 week old kittens. I used Frontline on her a month ago but her kittens have fleas anyway. I know that I can't put Frontline on the mother while she's nursing.  I'm afraid the fleas will kill the kittens.  I ordered some powder from an all natural pet store. It's made from some kind of rock and destroys the fleas protective shell, but claims to be harmless to the mother and babies. Haven't received yet so we'll see. Do you have any suggestions?  

Answer
I would apply Advantage to the mom.  I do believe it is safer for her than Frontline, and if the babies still have fleas after 2 days, you could break open another tube of Advantage and put one dot on each of their heads.  Be careful about powders...even though all natural, can cause respiratory problems in kittens.