Small child's bed we reduced by 50% for writer (6)
I believe the answer is:
scribe
'writer' is the definition.
(scribe is a kind of writer)
'small child's bed we reduced by 50' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'child's bed' becomes 'crib' (bed for a baby or young child).
'reduced by 50' suggests halving the letters (50 percent of the word is removed).
'we' halved is 'e'.
's'+'crib'+'e'='SCRIBE'
'for' is the link.
(Other definitions for scribe that I've seen before include "Writer (before printing was developed)" , "Write" , "Document copier (hist.)" , "Medieval clerk" , "Clerk, a public copyist" .)