Musannaf Ibn Abi Shaybah 810 — A woman performing ghusl: does she undo

Nafi' said: The wives of Sayyiduna Ibn Umar (may Allah be pleased with them both) and the mothers of his children (his slave women who had borne him children) did not undo their hair for the ritual bath of menstruation and janabah; however, they would wet it very thoroughly.