Legal Question in Family Law in Washington

Get a lawyer and file for custody. The jurisdiction of the custody case will be according to the Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA), which has been passed in all states essentially the same. In WA it is found in chapter 26.27 RCW. If you google UCCJEA, you will find a number of articles on the internet that discuss it.

No state will have jurisdiction unless the kids have lived there for 6 months. If less than 6 months, Washington has jurisdiction under the UCCJEA because it is the home state of the children. Get a lawyer and file for custody. She will have no choice to fight the case here. And you might be able to get an order from the court to bring the kids back.