My DD came home yesterday from school with headlice, yuk! I got some hedrin from chemist and did her head last night. Problem is I don't think I put enough on or did it well enough as I found one this morning and one this evening, alive. Do I give her head a proper go tonight again with hedrin?? Or do I just wait the 7 days?? Ive done the combing and conditioner this afternoon,why am I still finding them?