(a) Any adult person may petition to adopt a child if the person:

(1) Is at least 25 years of age or is married and living with his spouse;

(2) Is at least ten years older than the child;

(3) Has been a bona fide resident of this state for at least six months immediately preceding the filing of the petition; and

(4) Is financially, physically, and mentally able to have permanent custody of the child.

(b) Any adult person, including but not limited to a foster parent, meeting the requirements of subsection (a) of this Code section shall be eligible to apply to the department or a child-placing agency for consideration as an adoption applicant in accordance with the policies of the department or the agency.

(c) If a person seeking to adopt a child is married, the petition must be filed in the name of both spouses; provided, however, that, when the child is the stepchild of the party seeking to adopt, the petition shall be filed by the stepparent alone.