Mujahid relates that Sayyidah Umm Salamah (may Allah be pleased with her) said: O Messenger of Allah, we are not given an (equal) share of inheritance, nor can we fight and attain martyrdom. So Allah Almighty revealed the verse: "And do not wish for that by which Allah has favoured some of you over others" [Surah al-Nisa: 32] to the end of the verse. Then this verse was revealed: "I do not allow the deed of any doer among you to be lost, whether male or female" [Surah Al Imran: 195].
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19913