Is it permissible for a father to give the surplus rental income from his building to my unmarried siblings without the consent of the married siblings?

If a father gives money to one of his needy children (male or female) as an allowance for a necessity, and withholds from those who are not in need, there is no blame upon him. Examples include an allowance for a student's studies or for a sick person's medical treatment. The need should be estimated appropriately without excess. However, it is not permissible to exclusively grant them an absolute gift unless the others agree, or unless the others are given a similar amount; this is because justice between children in gift-giving is obligatory.