What is the ruling on a husband concealing his sister-in-law’s money without her knowledge or her husband’s knowledge?

A woman has independent financial solvency and the right to dispose of her wealth as long as she is of sound mind. This is by agreement among jurists regarding disposal through exchange. The majority of scholars permit her to donate all of her wealth, while the Malikis and a narration from Imam Ahmad held that she may only donate one-third of her wealth, and anything beyond that requires the husband's permission.

If the wealth is the wife's private property, she has the right to dispose of it and keep it wherever she wishes, especially if the husband is wasteful or oppressive. However, if it is the husband's wealth or saved from his expenses, then it is not permissible for her to do so.

The marital relationship should be based on honesty and good companionship. Financial independence does not mean that the wife should dispose of her wealth without consulting her husband. Rather, she should comfort him with her wealth, especially when he is in need.