It is narrated from Sayyidah Umm Waraqah bint Nawfal (may Allah be pleased with her) that she said: When the Prophet (peace and blessings be upon him) set out for Badr, I said: O Messenger of Allah! Permit me to go out with you on the expedition, to treat your wounded and nurse your sick; perhaps Allah will grant me martyrdom. He (peace and blessings be upon him) said: "Stay in your house, for Allah will surely grant you martyrdom." She used to be called "the martyr", and she had read the Qur'an. She asked the Prophet (peace and blessings be upon him) for permission to set aside a place in her house in which to pray, and he (peace and blessings be upon him) gave her permission.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21789