The Prophet ﷺ performed the funeral prayer over a woman who had died in childbirth, and he stood at the middle of her body.
حدثنا يزيد بن هارون أخبرنا حسين يعني المعلم عن عبد الله بن بريدة
أن النبي ﷺ صلى على أم فلان ماتت في نفاسها فقام وسطها
Its isnad is sahih, and it is found in Bukhari 3/201, no. 1331, Fath, and Muslim 2/664, no. 964, and Abu Dawud in the book of funerals, chapter on where the imam stands relative to the deceased. And Tirmidhi 3/344, no. 1035, where he said, hasan sahih, and Nasai 4/70, and Ibn Majah 1/479, no. 1493.