What is the ruling on stealing things that family members hide, such as sweets and other items?

A Muslim's property is inviolable and may not be taken without his permission, as the Prophet, peace and blessings be upon him, said: "Every Muslim's blood, property, and honor are sacred to another Muslim." Therefore, it is not permissible to take from the family's property without their consent. If the theft occurred before puberty, there is no sin, but the money or its equivalent must be returned. However, if it occurred after puberty, the person is sinful and must repent and return the money or its equivalent.