I'm a Notary Public in WA and was asked to notarize some documents from someone in CA while they are in WA is that legal?

So long as you have documentation of the events then it should be legal. As to the fact that your job is to legally verify the person signing the document is who they say they are and all the state rules were followed. Also in the case of out of state persons I would also take a picture of them for the files. That way with the copies of ID they gave you along with their picture your covered.

At least here in GA, you may notarize anay doctument within your state, so if they have the paper in person in your state you can.