minor paid fine for taking item from store, under WA law can the minor face criminal charges

I presume, from reading your post, that you paid the civil demand from the store. These claims are made pursuant to RCW 4.24.230. There are two types of claims in a theft - civil and criminal. The money you paid is likely for the civil claim that the store had against you. Your payment, simply prevents the store from bringing the civil claim. The Prosecutor (the State) can still press charges for the criminal claim, if they wish to do so.
However, you may qualify for compromise of misdemeanor (see the link below) if you simply repaid the victim. There are some additional steps for obtaining a compromise of misdemeanor and you should consult with your attorney.