Daughter brought in spare pen after revising parts of book (9)

I believe the answer is:

endpapers

I'm a little stuck... Click here to teach me more about this clue!

'parts of book' is the definition.
I know nothing about this answer so I can't tell whether this works.

'daughter brought in spare pen after revising' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'brought in' indicates putting letters inside.
'after revising' indicates anagramming the letters.
'spare'+'pen'='sparepen'
'sparepen' with letters rearranged gives 'enpapers'.
'd' put inside 'enpapers' is 'ENDPAPERS'.

Can you help me to learn more?

(Another definition for endpapers that I've seen is " sheets inside cover of book".)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.