Hi Kali,
Hope your kitty is doing better. Heavy Flea infestation can easily cause anemia (the fleas are literally sucking the "life's blood" out of her. Bathe her using dish soap, keep it on once lathered for 10 minutes (it kills the fleas)and then rinse well. Brush her often to disturb any remaining fleas and clean her sleeping area etc. You can bathe her once a week for a maximum of 3-4 weeks. Flea infestation is usually just a symptom of something more serious, healthy animals repel fleas on thier own. Good luck.