Hoping the condition of the tire can provide information on how it came to be flat. Example - did it flatten due to hitting something in the road, nail, sliced ?
Is that road fairly busy? Amy cameras? If so , like the other poster said , chances are someone saw a car stop at hers. I feel she had to know or trust the person who stopped to "help". Could the flat been planned ahead of time and the person who did it followed her?
The other scenario is someone random took advantage of the situatilon and confronted her with a weapon to make her get out of the car. I say a weapon because I would think that unless she was going to change the tire on her own and was out of the car, she would be sitting with all doors /windows locked until help arrived - police or auto service. I have female friends who can change a tire but I myself would call road service.