Oh, boy...hmmmm...probably easier to have her declared dead. Have you spoken with your states child support enforcement unit? There are also other private recovery companies, but I hear they take a nice chunk..considering you have nothing now, might be worth looking into at least. A private detective can easily trace her out by social security number if you have it (check court papers) You can also try checking the Federal prisoner registry and different state criminal background checks....might turn up something there?
Just a thought.
KAT