She used to comb the hair of the Messenger of Allah ﷺ while she was menstruating and he was in spiritual retreat. He would extend his head to her while she was in her room.
أخبرنا نصر بن علي قال حدثنا عبد الأعلى قال حدثنا معمر عن الزهري عن عروة
أنها كانت ترجل رأس رسول الله ﷺ وهي حائض وهو معتكف فيناولها رأسه وهي في حجرتها
Bukhari narrated it in Itikaf, chapter "The person observing itikaf puts his head into the house for washing," Hadith 2046, from the narration of Mamar, and Muslim narrated it in Hayd, chapter "The permissibility of a menstruating woman washing her husband's head... etc.," Hadith 297, from the narration of Urwa, with this wording.