Sufyan bin 'Uyaynah سفيان بن عيينة · The Book on Sacrifices

"We were with the Messenger of Allah (ﷺ) on a journey when the (Day of) Adha came, so we shared seven for a cow and ten for a camel."

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."