What stage of moral reasoning do the children in Harry Potter and the Philosopher's Stone appear to be in?

Answer 1

Throughout the book, Harry Potter and Ron Weasley are eleven years old and Hermione Granger is twelve years old.

The characters tend to be at level 2 - Conventional Mortality. But also show signs of their development into the third stage as they realise that sometimes, rules have to be broken to save something else. For example, saving the philosopher's stone is much more important than staying in past curfew and Hermione even curses Neville Longbottom to allow them to go ahead.