Musnad Abu Ya'la al-Mawsili 117:21

Bishr narrated to us, Ja'far narrated to us, from Thabit, from Anas, that the Messenger of Allah (peace and blessings of Allah be upon him) used to go on military expeditions with Umm Sulaym, along with women from the Ansar. They would provide water and treat the wounded.