What should I do about taking money from my brother who earns his money from both lawful and unlawful sources, and must I inform the family about this?

The brother should be advised to repent and restore the rights of the wronged, because whoever has wronged his brother should seek his forgiveness before there are no dinars or dirhams.

A Muslim must avoid what is unlawful in his food, drink, and clothing, as this is a reason for prayers not being answered.

The family must be informed of the matter so that they are aware of it. It is preferable to avoid eating from this money, but there is no sin upon the needy person in eating from it as long as the money is mixed, until he becomes self-sufficient.