¶25 First, mother contends that the Department did not meet its obligation to exercise due diligence to work with the Tribe to determine whether the children were Indian children. See People in Interest of L.L. , 2017 COA 38, ¶ 29, 395 P.3d 1209 (when there is reason to know a child may be an Indian child, the department must exercise due diligence to identify and work with relevant tribes); see also 2016 Guidelines at 11. But, as discussed above, the juvenile court already had sufficient information at the temporary custody hearing to determine that the children were Indian children.