It is ok if she does not wash her hair with shampoo. In the olden days when people were not worried about hygiene, it would be ok. But in 2008, we wash with soap or anything that will get the dirt or bacteria off. If ther was someone who said they had not showered in 11 years, but rinse once a month everyone would be yelling gross huh, we . As a black person, I know many women who go months without washing their hair, it does not smell at first, but it eventually does. If she is happy, good for her. But I am not picking it up even if it will grow my hair to Hip length
But if you ever work with animals, on a farm, hospital, construction site or laboratory and actually
get dirt on you, please wash with soap and shampoo. As a doctor and Biologist, I know that there is nothing cleansing about sebum, nothing!!