Nitpick

[joywitch_m_curmudgeon]

Ok, I'm re-reading now, so this time I've got my LOON hat on, and I 
may have spotted a discrepancy.  It has to do with the trio's OWLs.

Harry and Ron each get 7 OWLs and fail 2 exams.  IOW, they took 9 OWL 
exams.  Hermione gets 11 OWLs.  But Hermione wasn't taking TWO more 
classes than Ron and Harry, she was taking 1 more class.  Harry and 
Ron had 2 electives -- Divination and Care of Magical Creatures.  
Hermione starts out taking all of the 5 electives, but then drops 2 
(Div and Muggle Studies) after her third year, so she had 3 
electives -- or ONE more class than Harry and Ron.  That means she 
should have taken 10 OWL exams, not 11.

IOW, Hermione received her 11 OWLs in:

1. Astronomy
2. Care Of Magical Creatures
3. Charms
4. DADA
5. Herbology
6. History of Magic
7. Potions
8. Transfiguration
9. Ancient Runes
10. Arithmancy
11. ?????