There is not really sufficient information. If the existing order was issued in Nevada, and you remained in Nevada, Nevada has Continuing Exclusive Jurisdiction ("CEJ") to issue further orders even if the kids have been gone for a year. If the facts are different, or there is no underlying court order, the analysis is different; the relevant rules are explained in "The Basics of Family Law Jurisdiction" along with an easy-to-use flowchart, all posted here. It is probably best for you to consult with a Family Law specialist who understands jurisdictional issues as quickly as possible.
Answered on Mar 15th, 2018 at 2:05 PM