Maliks Muwatta Book 2, Hadith Number 72.
Section : How to do Ghusl for Major Ritual Impurity.
Yahya related to me from Malik that he had heard that A’isha was asked about how a woman should do ghusl for major ritual impurity. She said, “She should scoop water over her head with both hands three times and rub the roots of her hair with her hands.”