Muhammad bin Yahya bin Hiban محمد بن يحيى بن حبان · The Book on Sacrifices

That she asked the Messenger of Allah (ﷺ) about the 'Aqiqah. He said: "For the boy is two sheep, and for the girl is one, it will not harm you if they (i.e. the sheep) are male or female."

That the Messenger of Allah (ﷺ) said: "The boy is mortgaged by his 'Aqiqah; slaughtering should be done for him on the seventh day, he should be given a name, and his head should be shaved."