Children’s writer reduced home a small amount (6)
I believe the answer is:
nesbit
'children's writer' is the definition.
(I've seen this before)
'reduced home a small amount' is the wordplay.
'reduced' means to remove the last letter.
'home' becomes 'nest' (a bird's home).
'a small amount' becomes 'bit' (a bit is a small amount).
'nest' with its final letter removed is 'nes'.
'nes'+'bit'='NESBIT'
(Other definitions for nesbit that I've seen before include "Edwardian author" , "Children's writer" , "Edith --, author of The Railway Children" , "Lady novelist" , "Edith ---, wrote Railway Children" .)