Musnad Ahmad 1268:3

Yahya ibn Sa'id narrated to us, from Ibn Jurayj, 'Ata' narrated to me, from Habibah bint Maysarah, from Umm Kurz al-Ka'biyyah, from the Prophet (peace and blessings of Allah be upon him): "For the boy, two sheep, and for the girl, one sheep."