A representative payee is appointed by a government agency to receive, manage and spend government benefits for a beneficiary. The representative payee’s authority is limited to only the government funds. Usually, this applies to Social Security. For more information, please refer to the Social Security Administration's website here.
If your family member receives veteran's benefits, you should contact the Department of Verteran's Affairs to ask them about their fiduciary program. you can access that website here.