Who was the first woman from the Ansar to pledge allegiance to the Messenger of Allah, peace and blessings be upon him?

Two women attended the Pledge of Allegiance (Bay'at al-Aqabah): Nusaybah bint Ka'b and Asma bint 'Amr ibn 'Adi. Their attendance is mentioned in several historical sources. However, it is not known which of them embraced Islam first.