(A) A final decree of adoption shall not be issued and an interlocutory order of adoption does not become final, until the person to be adopted has lived in the adoptive home for at least six months after placement by an agency, or for at least six months after the department of job and family services or the court has been informed of the placement of the person with the petitioner, and the department or court has had an opportunity to observe or investigate the adoptive home, or in the case of adoption by a stepparent, until at least six months after the filing of the petition, or until the child has lived in the home for at least six months. (B) In the case of a foster caregiver adopting a foster child or person adopting a child to whom the person is related, the court shall apply the amount of time the child lived in the foster caregiver’s or relative’s home prior to the date the foster caregiver or relative files the petition to adopt the child toward the six-month waiting period established by division (A) of this section.