If you file it in CA and win, then she can later argue that the CA courts had no jurisdiction
. Under those circumstances the Oregon courts may not honor the judgment (you'll need for the Oregon courts to honor the judgment in order to use various means of collection, such as garnishments, etc., if she refuses to voluntarily pay even after losing). Whether or not the CA courts have jurisdiction depends on the circumstances in which the contract was made. If she had visited you in person, then the CA courts would surely have jurisdiction, but since the contract was created via telephone, jurisdiction is definitely not a sure thing. If the CA courts have no jurisdiction, then you'll need to sue in Oregon, since they definitely have jurisdiction over an Oregon resident.
The botXXXXX XXXXXne is that if you sue in CA, there is a chance that you'll ultimately have to re-sue in Oregon. Whether you want to take that chance is up to you. You can just sue in Oregon now and not worry about the jurisdiction argument. Or you can sue in CA, and hope that she doesn't make a jurisdiction argument, or that if she does make such an argument, that you'll win that argument.
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