If a woman dies without having made expiation, do her heirs have to make expiation on her behalf?

Question: I have an elderly grandmother who has not fasted for ten years because she was unable to, and she passed away this year. She did not make expiation for the past years, and her heirs did not make expiation on her behalf either, due to their ignorance. Please note that she received assistance from the Social Security Office. Is it obligatory for the heirs to make expiation on her behalf for every day of fasting in Ramadan for the past years? And is there any sin on them for that? Please inform us, may Allah reward you with good.

Answer: If she was of sound mind during the period mentioned and was able to make expiation, then expiation must be paid from her estate for the days she did not fast and for which she did not make expiation. For each day, one poor person must be fed half a sa' (a dry measure of about 3 kg) of the local staple food, to be distributed to the poor and the needy.
However, if her mind had changed due to old age, or if she was poor in her lifetime and unable to make expiation because the amount allocated to her from social security was only enough for her needs with nothing left over for expiation, then she owes nothing, nor do her heirs, by the saying of Allah (Glorified and Exalted is He) : [Surat al-Taghabun: 16], and by the saying of the Prophet (peace and blessings be upon him): It is agreed upon that it is authentic.
And because with the presence of old age, if she had become very old, the obligation of fasting, prayer, and the like is lifted from her. And success is from Allah.