The last (I think) plot twist, that must be untwisted is the one about her. Of course I’m talking about Minerva McGonagall.
In Fantastic Beasts Crimes Of Grindelwald, we have this scene in our famous Hogwarts place, where a young Professor Dumbledore is being visited by the Minister of Magic during one of his lessons. He kindly asks his students to leave the classroom, nothing less with Minerva McGonagall. In fact we see a young Minerva, around the twenties. We are in the 1927.
Let’s make a few counts, in an Interview released by Rowling in 16th October 2000, she declares that McGonagall was around 70’s. In the 2000, was out Harry Potter and the Philosopher’s Stone, 7 years later McGonagall had 77 years, more or less and we are in the year 1998-1999 (year of the film Harry Potter and the Deathly Hallows) .
1999-77, it makes 1922 she would have been teaching Hogwarts when she was only 4 years old. It cannot be.
Moreover she tells in The Order of Phoenix to Umbridge that she started teaching Hogwarts in 1953 when she was 21, this reconnect us with her birthday date as the 4th October 1932.
Someone proposed her could be the mother of Minerva since she was a witch, but she cannot since her name was Isobel.
I, as always, want to repeat, that I FIRMLY believe in Rowling’s mind, and believe we need to wait all the five films to understand completely.. but in the meanwhile we can try to sort something out.
My theory, is that she’s using a Time-Turner to learn from Dumbledore. Or just to learn more that she could, let’s not forget she almost ended up in Ravenclaw. Moreover in the Prisoner of Azkban the Time-Turner Hermione had, she was given by McGonagall herself.
Muggle Worthy Case 