Legal Question in Family Law in Washington

When you were married overseas assuming a marriage license was issued to you at that time, that would be the controlling event to determine whether you are legally married. It should also be mentioned that the ceremony has to be performed by somebody legally qualified to do so in the jurisdiction overseas where you're married. A church ceremony anywhere in the United States that is unaccompanied by a marriage license is not a legal marriage, at least not in Washington. The marriage license is the key.

Having written the above, if the two of you are cooperating in seeking a dissolution of your marriage, I doubt the court will want proof that you were legally married in the first place so long as you both claim to have been married.