(a) The following words and phrases when used in this chapter shall have the following meanings, respectively, unless the context shall clearly indicate a different meaning in the connection used:

(1) AWARDING AUTHORITY. The State Board of Adjustment, created and existing pursuant to Article 4 of Chapter 9 of Title 41 of this Code.

(2) CHILD or CHILDREN. Such term includes posthumous children and all other children entitled by law to inherit as children of the deceased, also stepchildren who were members of the family of the deceased at the time of his death, and dependent upon him for support, also a grandchild of the deceased Alabama national guardsman, whose father is dead or is an invalid, and who was supported by and was a member of the family of such deceased grandparent at the time of his death.

(3) DEPENDENT CHILD. An unmarried child under the age of 18 years, or one over that age who is physically or mentally incapacitated from earning.

(4) ALABAMA NATIONAL GUARDSMEN. The officers and men commissioned or enlisted in the Alabama National Guard, army or air, as defined in Section 31-2-3.

(b) For the purposes of this chapter, the following described persons shall be conclusively presumed to be wholly dependent:

(1) A wife, unless it be shown that she was voluntarily living apart from her husband at the time of his death, or unless it be shown that the husband was not in any way contributing to her support and had not in any way contributed to her support for more than 12 months next preceding the occurrence of the injury causing his death.

(2) Minor children under the age of 18 years and those over 18 if physically and mentally incapacitated from earning.

(3) A wife, child, mother, father, grandmother, grandfather, sister, brother, mother-in-law, and father-in-law who were wholly supported by the deceased Alabama national guardsman, at the time of his death and for a reasonable period of time prior thereto, shall be considered his dependents and payment of compensation may be made to them as authorized in this chapter.

(c) Any member of the class named in subdivision (b)(3) of this section who regularly derived part of his support from the earnings of the deceased Alabama national guardsman, at the time of his death and for a reasonable time immediately prior thereto, shall be considered his partial dependent and payment of compensation may be made to such partial dependent as authorized in this chapter.