Sulaiman bin Yasir narrated that :

Abu Hurairah, Ibn Abbas and Abu Salamah bin Abdur-Rahman mentioned the pregnant women whose husband died and she gave birth after the death of her husband. So Ibn Abbas said: "She observes Iddah until the end of the two terms." Abu Salamah said: "Rather, she is allowed when she gives birth." Abu Hurairah said: "I am with my nephew," meaning Abu Salamah.So he sent a message to Umm Salamah the wife of the Prophet. She said: "Subai'ah Al-Aslamiyyah gave birth a short time after her husband died, so she sought the judgment of the Messenger of Allah and he ordered her to get married."

حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا اللَّيْثُ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، أَنَّ أَبَا هُرَيْرَةَ، وَابْنَ، عَبَّاسٍ وَأَبَا سَلَمَةَ بْنَ عَبْدِ الرَّحْمَنِ تَذَاكَرُوا الْمُتَوَفَّى عَنْهَا زَوْجُهَا الْحَامِلَ تَضَعُ عِنْدَ وَفَاةِ زَوْجِهَا فَقَالَ ابْنُ عَبَّاسٍ تَعْتَدُّ آخِرَ الأَجَلَيْنِ . وَقَالَ أَبُو سَلَمَةَ بَلْ تَحِلُّ حِينَ تَضَعُ . وَقَالَ أَبُو هُرَيْرَةَ أَنَا مَعَ ابْنِ أَخِي يَعْنِي أَبَا سَلَمَةَ فَأَرْسَلُوا إِلَى أُمِّ سَلَمَةَ زَوْجِ النَّبِيِّ ﷺ فَقَالَتْ قَدْ وَضَعَتْ سُبَيْعَةُ الأَسْلَمِيَّةُ بَعْدَ وَفَاةِ زَوْجِهَا بِيَسِيرٍ فَاسْتَفْتَتْ رَسُولَ اللَّهِ ﷺ فَأَمَرَهَا أَنْ تَتَزَوَّجَ .

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ.