Focus on Children Act This bill amends the Congressional Budget Act of 1974 to require the Congressional Budget Office (CBO) to produce studies and reports regarding federal spending on children. The CBO must provide: studies of legislation containing changes in spending on children, upon the request of a congressional committee; an annual report regarding spending on children; and an annual report on the President's budget request for spending on children. The CBO may provide a warning report to Congress regarding a fiscal year in which outlays for interest on the public debt will exceed spending on children. The CBO must also develop and maintain a public website that includes: the reports and studies required by this bill, a dashboard containing key indicators and visualization tools to assist the public in understanding trends in spending on children, and an open data portal that contains quantitative data on federal spending on children.