D.K.
My godmother taught my daughter in a matter of an hour. She had her stand up, and reach around. They have little arms and it is too hard while on the toilet. SO have your daughter stand up and move her arm around and do it front to back. I used the wet flushable wipes until she was more able to make sure she was clean. I would say at four you need to supervise too to make sure it is done correctly and her hands are well cleaned. My son is four and is still working on it, I do a double check to make sure it is done correctly and he has washed his hands well.