Is it permissible for a woman to perform ghusl for janabah while her hair is tied without being braided?

A woman is not required to undo her hair when performing ghusl (ritual bath) after janabah (state of ritual impurity). If her hair is tied without being braided (e.g., with a string), she is not obliged to untie it unless it prevents water from reaching the hair beneath, or if there are many strings used to tie the hair. In such cases, she must untie it.