It sounds like you're doing a pretty thorough job treating her, so it could be your house that's the problem. The adult fleas on your cat are only a VERY small percentage of the total flea population in the house (eggs, larvae, etc--there's a lot of stuff on the flea life-cycle online).
You can flea bomb like love.my.cats said, but I was hesitant to do that myself. I had luck using Borax, which is basically just boric acid--find it in the laundry detergent isle. It's relatively non-toxic (although you don't want anyone eating it
) and CHEAP. Basically you want to vacuum first, then sprinkle the stuff on all the carpet and upholstered furniture, let it sit (the longer the better, but 30mins should do--isolate cat during this process), and finally vaccuum a few times to make sure you get it all up.
When vacuming make sure to get underneath furniture, in cracks and crevices, all the corners, closets, etc--basically everywhere. Immediately afterward seal the vacuum bag and either dispose of it or stick it the freezer.
Also, obviously, you must wash all bedding and laundry in HOT water. And, unfortunately, the process should be repeated in another two weeks or so.
If you can't tell, I really hate fleas. Good luck!