Legal Question in Family Law in California

It is not actually your resident state unless you show an intent to remain there. You did state that you both live in CA, so it sounds more like your resident state is also CA. Get yourself a WA drivers license and have some bills sent to your address there (utilities are usually the best) and that should be enough to change your state of residency (in addition to the desire to remain in the state after your term of active duty is complete).

Once you accomplish this, then you should be able to show the requirements for residdency and can file in WA.

Scott