Northern Marianas Family Assistance Act This bill expands eligibility for the Temporary Assistance for Needy Families (TANF) program to include the Commonwealth of the Northern Mariana Islands (CNMI). It also makes certain TANF provisions, including those related to child support enforcement and mandatory work requirements, inapplicable to that territory. In addition, the Department of Health and Human Services must provide technical assistance to the CNMI on developing a plan to use its TANF funds; and seek to negotiate an agreement with the CNMI that sets out how the territory's work, employment, and training programs will be assessed.