What is the ruling on money taken from the husband without his knowledge, and must it be returned?

A wife is not permitted to dispose of her husband's money except with his permission. An exception to this is a small amount that is customarily overlooked, in which case she receives half the reward and her husband the other half. As for lending his money to her family or others without his permission, it is not permissible for her to do so, nor for them to take that money if they are aware [of the situation]. They must return it to its owner, and she must return what she took and repent.