Is it permissible to set aside a portion of the monthly household allowance that the husband allocates for his wife and children, subscribe with it to a cooperative society (jam’iyyah), and then later use it for personal or household matters, or as charity?

If the husband grants his wife and children ownership of the maintenance (nafaqah), then whatever remains after spending judiciously becomes the property of the wife and children. It should be spent on what benefits all of them, and the wife is permitted to give a small amount of it in charity. However, if the husband does not grant ownership of the maintenance to his wife, but rather gives it to her as his agent for spending, then she is not permitted to take anything for herself except with his consent. She is permitted to give a small amount of it in charity without his permission, but for a large amount, his permission is required.