I would also suggest going to the local social security office, although my experience has been that a lot depends on the luck of the draw. The first time, I got some great advice and help from someone who gave me plenty of time, and took care of all the details for me.
The second visit, about something else, I got a jackass who didn’t know anything, and I wasted half a day. So I went back again the next day, and fortunately got someone better.
But if you can get someone good, who is on your side and working for you, that would be your best solution.
I’m of the opinion that she will receive your step father’s social security retirement, and her teaching pension. Yes, she opted out of SS. As far as SS is concerned, she would be treated the same as a widow who was a homemaker, and never paid in. She would then receive the hubby’s SS.
But like the others have said, call them. And don’t make a big thing out of the fact that she opted out of SS.