Is it permissible for a man to marry the daughter of his deceased or divorced wife if she was not raised under his guardianship? And is the dispensation for this mentioned only in the school of Imam Ahmad, based on the hadith of Imam Ali?

It is impermissible for a man to marry the daughter of his deceased or divorced wife if the divorce or death occurred after consummation. This is the correct view according to the Hanbalis and the majority of scholars. It is not a condition that the stepdaughter (rabībah) must have been raised under the care of the husband for her to be forbidden to him. Although there is a difference of opinion on this matter from some of the Salaf and the Dhahiris, the majority of scholars hold that the condition mentioned in the Holy Qur'an, "فَإِنْ لَمْ تَكُونُوا دَخَلْتُمْ بِهِنَّ فَلَا جُنَاحَ عَلَيْكُمْ" (if you have not consummated with them, then there is no blame upon you), indicates that consummation with the mother is the sole condition for the prohibition, and that the phrase "in your care" (fī ḥujūrikum) is not an independent condition for the prohibition.