Legal Question in Family Law in Washington

The real answer is whether it really matters at this point. The following are ideas off the top of my head. Research might provide a better answer. You may want to contact the county Auditor's office and see how they have dealt with this issue in the past.

If your friend's primary concern has to do with inheritance or related issues, it would depend on how much value is at stake. Probably the first thing to do is to find the actual certificate if it exists and file it. (Talk with the people at the county auditor's office about this.) Also get as much evidence together showing they were married, such as wedding photos, guest list, newspaper announcement, pastor's certificate, other indications where he identified himself as her husband or her as his wife, etc. A number of affidavits/declarations from people who attended the wedding would be useful. It would probably be up to the court in a probate to resolve the matter.

If your friend's primary concern has to do with how it appears to others or the legitimacy of the children, there would still probably to be a probate.