The Messenger of Allah ﷺ sacrificed a single cow on behalf of the family of Muhammad during the Farewell Pilgrimage.
حدثنا ابن السرح حدثنا ابن وهب أخبرني يونس عن ابن شهاب عن عمرة بنت عبد الرحمن
أن رسول الله ﷺ نحر عن آل محمد في حجة الوداع بقرة واحدة
Sourcing, sahih. Ibn Majah reported it in the Book of Sacrifices, chapter on how many people a camel and a cow suffice for, hadith 3135, from Ibn Sarh, through this route. The hadith has a corroborating narration in Nasai's Sunan al-Kubra, hadith 4129, with a hasan chain of transmission.