“Person” when relating to one who dies, disappears, or becomes incompetent, prior to receiving payment, means a person who has earned a payment in whole or in part pursuant to any of the programs to which this part is applicable. “Children” shall include legally adopted children who shall be entitled to share in any payment in the same manner and to the same extent as legitimate children of natural parents. “Brother” or “sister”, when relating to one who, pursuant to the regulations in this part, is eligible to apply for the payment which is due a person who dies, disappears, or becomes incompetent prior to the receipt of such payment, shall include brothers and sisters of the half blood who shall be considered the same as brothers and sisters of the whole blood. “Payment” means a payment by draft, check or certificate pursuant to any of the Programs to which this part is applicable. Payments shall not be considered received for the purposes of this part until such draft, check or certificate has been negotiated or used.