Welfare to Work Act of 1997 - Amends part A (Temporary Assistance for Needy Families) (TANF) of title IV of the Social Security Act to: (1) rename the program the Assistance for Needy Families Program; (2) require work activities after three months of receiving program assistance (instead of the current 24 months), with certain good cause exceptions; (3) require cash benefits to recipients based on the number of hours engaged in required work activities; (4) increase child care funding; (5) eliminate the five-year limit on program assistance; (6) establish a supplemental grant for operation of work programs; (7) repeal authority for Federal loans for State welfare programs; (8) make mandatory the currently optional domestic violence certification with regard to State plans; and (9) eliminate State discretion with respect to an initial assessment of assistance recipients, making such assessments mandatory.