Child Welfare Workforce Support Act This bill establishes a demonstration grant program for state or local agencies, tribes, tribal organizations, and other entities that administer certain child welfare programs to support workforce recruitment, retention, and advancement. Specifically, the Department of Health and Human Services must award up to ten grants to states and counties, and up to three to Indian tribes, giving priority to entities with high rates of turnover in the child welfare workforce. Grant recipients must, among other activities, increase interest in careers in the child welfare workforce and provide mentoring, professional development, and other support services to new hires and other employees. In addition, they may use funds to update certain technology infrastructure.