Thanks to Chalicea for another lovely puzzle:-)
I haven't read the book so am unfamiliar with the character but I do recognise it as the username of a Forum member - in fact, when I first saw one her posts I remember telling her it was my favourite username ever:-)
I finished this quite a bit quicker than expected because I didn't think I was going to be able to differentiate between the two types of clues - in one group the wordplay leads to the answer plus an extra letter and in the other the definition and wordplay differ in length by one letter so, basically, an extra letter! However, I didn't make a single wrong choice so it must have been clearer than I first thought - hurrah for me 😀