The Department of Human Services shall provide direct child welfare services when not available through other public or private child care or program facilities. For purposes of this Section, “child welfare services” means public social services that are directed toward the accomplishment of the following purposes:
        (1) Preventing the problems that may result in the
    
neglect, abuse, exploitation, or delinquency of children.
        (2) Providing supportive services and living
    
maintenance that contribute to the physical, emotional, and social well-being of children who are pregnant and unmarried.
        (3) Providing shelter and independent living services
    
for homeless youth.