Senility removes Responsibility

Question :

I have a grandmother who is very old and she has not fasted in 10 years due to her lack of ability. She died this year and she did not expiate for the previous years nor did her heirs make expiation for her due to their ignorance. It should also be known that she was receiving help in the form of social security benefits. Are her heirs obligated to make expiation on her behalf for every fast of Ramadhan during the previous years, and is there any sin on them regarding that? Please benefit us with an answer, may Allâh reward you with good.

Answer:

If she had sound intelligence during the period of time mentioned and she was able to make the expiation, then it is given on her behalf from what she left as inheritance. This is in order to expiate the days that she did not fast and she did not make expiation for by feeding a poor person half a Sa' of food for each day from the food of the land to be distributed among the poor and needy people.

However, if she lost her intellect due to senility or she was poor in her life and unable to make expiation due to her money from the social security being only sufficient for her needs without anything being left for expiating, there is nothing due on her or her heirs. This is due to Allâh's Statement:
"So fear Allah a much as you are able."

It is also due to the Prophet's statement:
"Whatever I have prohibited you from, avoid it; and whatever I have commanded you with, do it as much as you are able."

The authenticity of this Hadith is agreed upon.

Also, with senility being involved - if she had become senile - then the responsibility for fasting, prayer and similar things is removed from her. And success is from Allâh.

Source:
Ash-Shaykh Ibn Baz
Fatawa Islamiyah, Vol. 3 Pages 285-286