Is a woman required to wash her braided hair if she performs ghusl from janabah and takes handfuls of water and applies them to her head?

The obligatory act in ritual bathing (ghusl) from major ritual impurity (janabah) is to ensure that water covers all hair, even that which hangs down. It is also obligatory for the water to reach the roots of the hair and the scalp. It is not necessary to undo braids, but water must reach all parts of the hair.