Legal Question in Family Law in Washington

Re: my wife met a guy online left me and daughter out of nowhere

I can't tell you what to do, but I can tell you some of the things you can do. You can do nothing (probably not a great choice), you can try to get your wife back (without hurting anybody), you can file for dissolution of marriage or legal separation (if the marriage is over-file for dissolution). If you file for dissolution of marriage or legal separation you should also consider filing a motion for temporary orders for a temporary parenting plan, child support and possibly for responsibility for maintaining and using the family home and other property (joint bank accounts come to mind).