Defending the Human Rights of Palestinian Children and Families Living Under Israeli Military Occupation Act This bill limits U.S. assistance to Israel and establishes reporting requirements related to Israel's activities in the West Bank and its expenditures for offshore procurement. (Offshore procurement involves spending U.S. security assistance from the Foreign Military Financing program on Israeli-origin rather than U.S.-origin defense articles.) Specifically, the bill prohibits the use of any funds that are made available for assistance to Israel to support (1) military detention, interrogation, abuse, or ill treatment of Palestinian children; (2) seizure, appropriation, or destruction of Palestinian property and forcible transfer of civilians in the Israeli-controlled West Bank; or (3) certain activities to facilitate unilateral annexation by Israel of West Bank territory. The Department of State must report on the nature and extent of such activities carried out by Israel. Further, the Government Accountability Office must submit to Congress a report on related topics, such as (1) identifying specific programs and items to which funds for offshore procurement in Israel have been allocated, (2) identifying all end-use monitoring to which Israel is subject with respect to U.S.-origin defense articles, and (3) assessing the extent to which offshore procurement funds have supported illegal Israeli settlement activity in the occupied West Bank.