Unless consent is not required under section 2-402 of this title, a petition to adopt a minor stepchild may be granted only if consent to the adoption has been executed by a stepchild who has attained 14 years of age and:
(1) the minor’s parents as described in subsection 2-401(a) of this title;
(2) the minor’s guardian if expressly authorized by a court to consent to the minor’s adoption; or
(3) an agency that placed the minor for adoption by the stepparent.