Fasting on behalf of a deceased person who did not make up Ramadan

Question:
Shaykh Salih, among the questions that reached us, this sister asks and says: A woman we know died and did not make up the month of Ramadan, because she gave birth to her daughter on the first day of it, but we are not sure whether she fasted it as a make-up or not? And no one from her family remembers. She says: Is it permissible for me to fast the month on her behalf, or what should I do? May Allah bless you.

Answer:
The Sunnah is that you fast on her behalf, and you will have a reward, if Allah wills. The saying of the Prophet (peace and blessings be upon him) As for the deceased person who was able to make up the fasts, but the deceased person who was not able to make up the fasts, no one fasts on his behalf, because he was not able to make them up, such as one who was ill and died while still ill, or one who was old and unable to fast; these are the ones for whom no make-up fasts are performed. Yes.