As you know, EVERYONE in New York State ( whether they go to public, parochial, or private schools !) has had to take those exams, which once were THE most difficult end of the year exams EVER devised by mankind.
Sadly, in the past several decades, the Regents have dumbed these exams SO far down, that they are practically WORTHLESS, so easy to pass that an imbecile could pass them, yet many, many kids are FAILING them.
By the time you & I were in high school, the 4 year English (this exam was on top of all of the yearly English tests )Regents exam. My mother got 100% on hers and held the record for doing so, for a very long time. NO way even the best of the best kids, from our era would have gotten anywhere even vaguely near that grade! I know, because the state had mailed my mother back her blue book, with a lovely letter recognizing her acumen and achievement.
I graduated NYS high school in 1984 and found the regents exams to be quite easy - although I was perhaps only one of two in my small high school to think so. The only exam I scored lower than 90 on was French (I blew the essay).
Your mother sounds like she is or was an amazing woman.