Not sure Queen's consumed by fashion (4)
I believe the answer is:
torn
'not sure' is the definition.
(someone deliberating between two options is torn)
'queen's consumed by fashion' is the wordplay.
'queen' becomes 'r' (r is abbreviation regina. e.g. in ER ).
'consumed by' means one lot of letters goes inside another.
'fashion' becomes 'ton' (I've seen this before**).
'r' placed into 'ton' is 'TORN'.
(Other definitions for torn that I've seen before include "Divided" , "'-- Curtain', 1966 Hitchcock film" , "Undecided between two" , "Ripped - undecided" , "?Curtain (Hitchcock thriller)" .)