A. The following persons shall be conclusively presumed to be dependents wholly dependent for support upon the deceased employee:
1. A spouse upon his deceased spouse whom he had not voluntarily deserted at the time of the accident or with whom he lived at the time of the accident, if he is then actually dependent upon his deceased spouse;
2. A child under the age of 18 upon a parent and a child over such age if physically or mentally incapacitated from earning a livelihood or a child under the age of 23 if enrolled as a full-time student in any accredited educational institution; and
3. Parents in destitute circumstances, provided that there are no total dependents pursuant to other provisions of this section.
B. As used in this section, “child” includes a stepchild, a legally adopted child, a posthumous child, and an acknowledged illegitimate child, but does not include a married child, and “parent” includes stepparents and parents by adoption.