Easy to file a FOIA on Form G-639. Useless unless you know what you're looking at. Get a lawyer, please.

You may need to have her file an I-824. https://www.uscis.gov/i-824

This is the information for a FOIA: https://www.uscis.gov/g-639

Note, if you are out of status, you probably can NOT file for an adjustment of status.

Talk to an attorney via Skype for confirmation/clarification.

The short answer- Maybe. You may be able to adjust your status, despite having overstayed your H1B nonimmigrant visa, depending on the category under which the petition on your behalf was filed. You may be able to obtain your records from the USCIS using this link- https://www.uscis.gov/about-us/freedom-information-and-privacy-act-foia/how-file-foia-privacy-act-request/submitting-foia-requests.
However, considering the ULP issues in your case, I would advise you to hire an experienced immigration attorney to do a comprehensive assessment of your case, and determine the best route for you to obtain a green card.

Instructions for Requesting USCIS Records

You can mail or fax all FOIA requests to the USCIS National Records Center:
U.S. Citizenship and Immigration Services
National Records Center, FOIA/PA Office
P.O. Box 648010
Lee's Summit, MO 64064-8010
You can also call, fax or forward an email to USCIS:
Live Assistance: 800-375-5283
Fax: 802-288-1793 or 816-350-5785
uscis.foia@uscis.dhs.gov
As to adjusting status with USCIS, you should be in lawful status at the time of filing the FORM I-485.