Not up for Enid Blyton's first novel? (2,3)
I believe the answer is:
in bed
'not up' is the definition.
(I've seen this in another clue)
'enid blyton's first novel?' is the wordplay.
'blyton's first' becomes 'b' (1st letter of 'blyton').
'novel?' is an anagram indicator (letters in a new or novel order).
'enid'+'b'='enidb'
'enidb' with letters rearranged gives 'IN BED'.
'for' acts as a link.
(Other definitions for in bed that I've seen before include "Lying, possibly" , "Retired?" , "10 [AT REST] ," , "Not yet up" , "as 15 Down [GARDENERS] may be?" .)