The girl felt unwell coming back (5)
I believe the answer is:
delia
'the girl' is the definition.
'felt unwell coming back' is the wordplay.
'felt unwell' becomes 'ailed' (I've seen this in another clue).
'coming back' is a reversal indicator.
'ailed' backwards is 'DELIA'.
(Other definitions for delia that I've seen before include "-- Smith, TV cook" , "Girl" , "Woman" , "-- Smith, TV chef" , "-- Smith, cookery writer" .)