From Sahih Bukhari (Hadith 6910):
Narrated Abu Huraira:Two women from Hudhail fought with each other and one of them hit the other with a stone that killed her and what was in her womb. The relatives of the killer and the relatives of the victim submitted their case to the Prophet (ﷺ) who judged that the Diya for the fetus was a male or female slave, and the Diya for the killed woman was to be paid by the 'Asaba (near relatives) of the killer
Reference: Bukhari 6910