Musannaf Ibn Abi Shayba 9:1210

Ibn ‘Uyaynah narrated to us, from ‘Amr, from Abu al-Sha’tha’ and ‘Ata’, regarding the woman for whom a dowry (mahr) is to be determined, but [the husband] dies before he determines it: They both said: "She has the inheritance, and she has no dowry."