If CBP and USCIS can’t find a record or your wife’s entry, try submitting affidavits from individuals whom she traveled with if you can get them. In any event, she should file her adjustment application. If USCIS denies it, the agency will refer the case for deportation proceedings. Immigration judges are more generous in these cases than USCIS officers. She has a good chance of winning her case. Of course, it’s best if you get an immigration law expert to help with this case. It’s tough, but winnable.