750 ILCS 50/3

Who may be adopted. A male or female child, or an adult, may be adopted, provided the other conditions set forth in this Act are met, and further provided, with respect to an adult, that such adult has resided in the home of the persons intending to adopt him at any time for more than 2 years continuously preceding the commencement of an adoption proceeding, or in the alternative that such persons are related to him within a degree set forth in the definition of a related child in Section 1 of this Act.