The following persons, and they only, shall be deemed dependents and entitled to income benefits under the provisions of this act:
(1) A child: Under eighteen (18) years of age, or incapable of self-support and unmarried, whether or not actually dependent upon the deceased employee;
(2) Under twenty-three (23) years of age if a full-time student and as provided for in section 72-412(3), Idaho Code.
(3) The widow or widower only if living with the deceased or living apart from the deceased for justifiable cause, or actually dependent, wholly or partially, upon the deceased.
(4) A parent or grandparent only if actually dependent, wholly or partially, upon the deceased.
(5) A grandchild, brother or sister only if under eighteen (18) years of age, or incapable of self-support, and actually dependent wholly upon the deceased.