Who are the two female martyrs of the Pledge of Aqabah?

There was no fighting in the First or Second Pledges of al-Aqabah that would necessitate the presence of martyrs. Perhaps the question refers to the women who attended the Second Pledge of al-Aqabah, namely Umm Ammarah Nusaybah bint Ka’b and Umm Mani’ Asma bint Amr. Umm Ammarah mentioned that the Prophet, peace and blessings be upon him, gave his pledge to her and Umm Mani’ with words, without shaking hands.