If your stepmother's petition on your behalf were to be ultimately denied, due to USCIS alleging marriage fraud in your father's and stepmothers marriage, your application for green card will also be denied and you too will be asked to leave the country or referred to Immigration Court where you will be placed in removal proceedings together with your father. Kindly note that the burden of proving marriage fraud is entirely on CIS and IMmigration judges strongly hold them to the burden. Marriage fraud is not easy to prove. I hope you when your father have a good immigration lawyer.
Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
You are 25, so you may have aged out from the step-mom's petition. Have you considered applying for DACA? Sounds like you may be eligible. Speak with an attorney in person.
This is not legal advice and a client attorney relationship is not created.
As a 25 year-old, you are not an "immediate relative" of either your father or stepmother, nor are you of an age to be included as a "derivative" on any application your stepmother may have filed for your father. It is not clear whether you currently have legal status in the United States (e.g. are you studying on an F1 student visa?) If you do not have status now, there is no way you could get a green card through your father or stepmother without leaving the country, which may subject you to a 10-year bar from returning. The situation as you describe it raises many questions. You really should have an in-depth consultation with an immigration attorney before filing anything.
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