What is the ruling of Islamic law on a wife taking the amount allocated for car fare to transport the children to school, and walking instead of riding to use the remaining amount to buy household and children's necessities, except in cases of time constraints or rain?

It is permissible for a wife to take from her husband's money, without his permission, what suffices her and her children in a reasonable manner, if he does not spend on them reasonably. However, if he does spend on them reasonably, then she has no right to take from his money without his permission. And what he gives for the transportation of the children may not be spent on anything else except with his permission. The obligatory maintenance for the wife is what suffices her in a reasonable manner regarding food, housing, and clothing, taking into consideration the circumstances of both spouses.