Fraud due to lying to CBP is the real issue here. I think that will be the biggest factor, whether you apply for AOS in the US or she leaves and you petition the CR1 —you seem to be in the same boat, either way, in the sense that she committed fraud against USA. You should really find an attorney who specializes in overstays and AOS, as they are going to have all the relevant experience that you guys need. I have a feeling AOS within the country is going to probably be the better choice between the two.