Not any of it, sister said? (4)
I believe the answer is:
none
'not any of it' is the definition.
(none of it)
'sister said?' is the wordplay.
'sister' becomes 'nun' (sister is a term of address for a nun).
'said?' shows a homophone (sound like).
'nun' sounds like 'NONE'.
(Other definitions for none that I've seen before include "Nobody - nothing" , "Not one thing" , "0?" , "Not a soul" , "Not a thing or person" .)