Deliberately not Offering the Prayers
Question :

Is a son required to offer the lapsed prayers and fasts of his deceased mother if the parents deliberately abandoned the praying and fasting without any good reason, is the son still obligated to make them up on their behalf?

Answer :

It is not obligatory for the children to make up the prayers and the fasts that their mother missed, although it is strongly recommended to do so. If the father did not care about making up the prayers and the fasts that he missed, then it is not obligatory on his sons to make them up after his death.

Prayers on Behalf of Parents
Question :

Can we offer prayers on behalf of our parents while they are alive or are they only to be offered after they pass away?

Answer :

It is not permissible to offer the qadha prayers on behalf of a living person.

The Obligation of the Eldest son
Question :

Is it obligatory for the eldest son to perform the qadha for both parents?

Answer :

No, it is not obligatory to perform the qadha for the mother.

More than One Person Making up the Prayers
Question :

I have hired various persons who are poor and pious believers and mostly careful in Sharia laws to make up for the lapsed prayers of my late wife. Now I have been told that they cannot offer prayers at the same time. Is this true?

Answer :

It is not a requirement in the prayers on behalf of the deceased that they are not offered at the same time. They can offer the prayers based on their own circumstances and time.