At 17 my friend had a green card that was quickly stolen, then she went back to Canada. This was 20 years ago

If your friend went back to Canada 20 years ago, the green card is invalid as she would have abandoned it by not coming back to the US within one year of leaving. She would have to qualify all over again if she wishes to permanently immigrate to the US. The border is closed for nonessential travel, but your friend may still be able to enter the US by travel through air instead of land and sea. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.