Muggle-Born McGonagall?

[Eric Oppen]

No: HPFGUIDX 81349

One thing to remember about Professor McGonagall is that when we meet her,
she's "a sprightly 75" according to Herself.  If she was muggle-born, she
joined the Wizard World 64 years or so before the start of PS/SS.  Plenty
enough time, I think, for her to pretty much drop her "muggle"
ways-of-thinking and identify completely with the Wizard World.

By the end of her life (may it be long) Hermione may well be very much
changed from the girl we now know, who's still heavily influenced by her
Muggle upbringing.