A stepparent may file a petition under this Article to adopt a minor who is the child of the stepparent's spouse if:
(1) The parent who is the spouse has legal and physical custody of the child, and the child has resided primarily with this parent and the stepparent during the six months immediately preceding the filing of the petition;
(2) The spouse is deceased or incompetent but, before dying or being adjudicated incompetent, had legal and physical custody of the child, and the child has resided primarily with the stepparent during the six months immediately preceding the filing of the petition; or
(3) For cause, the court permits a stepparent who does not meet the requirements of subdivisions (1) and (2) of this section to file a petition.