I am so sorry to hear that! My son had head lice on 2 different occasions - I know how you feel. For starters you have to treat your house too. Everything should be vacuumed. Or sprayed with the spray they sell. Next all dolls, stuffed animals should be bagged for at least 2 weeks. Throw out or boil, or bag all hairbrushes, ponies, etc. Wash and dry ANY clothing that might have been in contact with lice. Don't forget to treat your car/ daughter's carseat. Bedding has to be washed and dryed. Lice can live for several days without food and can "hideout" on a favorite toy, etc.
To treat the lice on your heads try olive oil. Saturate the head/ hair shaft with it. Wear a tight shower cap for 8 hours, this will smother them. Then begin the painstaking process of making sure you comb them all out. The olive oil really helps with this. It will not kill eggs, so make sure you comb them all out!
If these measures fail, there are very strong prescription meds out there available from your pediatrican. GOOD LUCK!