Chaperone expected girl back (6)
I believe the answer is:
duenna
'chaperone' is the definition.
(I know that duenna is a type of chaperone)
'expected girl back' is the wordplay.
'expected' becomes 'due' (similar in meaning).
'girl' becomes 'ann' (woman's name).
'back' says the letters should be written backwards.
'ann' back-to-front is 'nna'.
'due'+'nna'='DUENNA'
(Other definitions for duenna that I've seen before include "Spanish chaperon or governess" , "Chaperone in Madrid" , "governess in Spain" , "Governess, chaperone" , "Female companion[" .)