Child's Support
Question :

How are the expenses of the child's upbringing calculated in the Sharia?

Answer :

It is obligatory on the father to support the children by providing them with food and drink, clothes, medicine, housing and all that they need for their living.

Mother's Obligation to Support the Children
Question :

If the father or the paternal grandfather does not support the children, is their mother obligated to do so?

Answer :

Yes, she is obligated to do so if she can afford it.

Mother's Expenses
Question :

Is one obligated to provide food and shelter for the wife or the mother?

Answer :

It is compulsory for a person to provide shelter and food for both of them when possible, and if it is not possible then the wife has precedence.