Tough one. But if she's on interpol, soon enough, they'll link it to your address. "Ooo shoopp, here she is. She went to US, got a GC at this office. Here's her number and her hubby's and their address."
Honestly, if she's on interpol AND you now became aware, I'd call it in. Why? You won't be able to wiggle your way later when interpol comes knocking and they ask when you knew and why you didn't report as soon as you knew. And just like that, her problem became yours.
If I were you, I'd call it in. I'm sure local police have connection to interpol. And then get a divorce while she's going in. Easy divorce that way.
P.S. Doing it as I suggested may be a blessing and dislodge you from that I-864 obligation. Why? You divorce and she may be forced into signing I-407 on her way out.