Abdullah bin Abbas reported,
The Prophet ﷺ reported that a woman came to him and said, "My mother has died, and she owed the fast of the month of Ramadan. Should I make it up on her behalf?"He asked, "Tell me, if she had owed a debt, would you have paid it for her?"She replied, "Yes."He said, "Then the debt owed to Allah 
is even more deserving of being paid."
Ahmad 3420
Sahihحدثنا ابن نمير حدثنا الأعمش عن مسلم البطين عن سعيد بن جبير
عن ابن عباس
عن النبي ﷺ قال أتته امرأة فقالت إن أمي ماتت وعليها صوم شهر رمضان فأقضيه عنها قال أرأيتك لو كان عليها دين كنت تقضينه قالت نعم قال فدين الله عز وجل أحق أن يقضى
Its isnad is sahih, and it carries the same meaning as 2137. See also 2224, 3377, 3378. This narration explicitly states that the question concerned making up missed fasts of Ramadan, and Hafiz did not refer to it in Fath al-Bari 4:169-170. It appears that the incidents of questioning were repeated, sometimes about a vow and sometimes about Ramadan, with the questioner being at times a man and at times a woman.