An insane elderly person is not obliged to pray or fast
I have a wife who is around 85 years old.
She is a righteous Muslim woman who has been suffering from diabetes for the last few years. Her condition has reached the extent that some days she is in a coma in the hospital and some days at home. She cannot speak properly and is not aware of what she is saying. Moreover, she cannot walk except with the help of her children. The problem is that she has not offered Salah (Prayer) for at least two years. With regard to Sawm (Fast), we pay expiation on her behalf, but with regard to Salah she does not even know the prescribed times of Salah or what to say while offering them. The mistakes in her speech are more than that which is correct. (Part No. 10; Page No. 169) Please answer the following questions for me: Is she required to offer Salah though her mind is not fully functioning? Are we required to pay expiation on her behalf for the days of Ramadan that she cannot fast? What should we do about the religious duties that are obligatory upon her? I ask Allah (the Most Exalted) to grant you good health. May Allah's Peace, Mercy, and Blessings be upon you!
If the case is as you have mentioned, then she is not required to offer Salah or to observe Sawm, because she is not Mukallaf (person meeting the conditions to be held legally accountable for their actions).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.