The wife of Zayd bin Thabit (may Allah be pleased with him) said: One day Zayd bin Thabit came to me and said: If you have a need, shall we speak to him about your inheritance from your father? For the Commander of the Believers, Umar bin al-Khattab (may Allah be pleased with him), has made the unborn child an heir. And Umm Sa'd was in the womb at the time her father was killed. Umm Sa'd said: I will not take anything from my sisters.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12488