She was headmistress for a short time after Dumbledore died, as a fill in. Then Snape took the job. After the battle was over Minerva reclaimed her place as headmistress for a few years before retired by 2017.
Minerva McGonagall who was also Deputy Headmistress and Transfiguration professor. A few times throughout the novel she was a stand in headmistress. After the novels finish many people believe her to have become the headmistress however, JK Rowling has stated that a new headmistress took over and McGongall retired.
Minerva McGongall.
In the Harry Potter books, Albus Dumbledore is the headmaster and Minerva McGongall was the deputy headmistress. Twice during the series, McGongall became acting headmistress, once in the 1992-1993 school year when Dumbledore was removed by the Board of Governors and once in the 1996-19997 school year after his death. In the 1997-1998 Severus Snape was appointed as the headmaster. It is not known who filled the position after that, although J.K Rowling has stated that it was not McGongall.
Minerva
Minerva McGongall is Scottish and has a Scottish accent.
No, Minverva McGongall is Scottish.
Yes she is.
It was never mentioned.
Harry Potter's headmaster is Professor Albus Percival Wulfric Brian Dumbledore
Eventually, but not during the books.
she becomes the headmistress at hogwarts!
Yes, she played Minerva McGongall as she has done in the previous films.