Girl? One may be hugged by mother returning (4)
I believe the answer is:
maid
'girl?' is the definition.
(maid is a kind of girl)
'one may be hugged by mother returning' is the wordplay.
'one' becomes 'I' (Roman numeral).
'may be hugged by' is an insertion indicator.
'mother' becomes 'dam' (female parent of an animal).
'returning' shows that the letters should be reversed in order.
'i' going inside 'dam' is 'diam'.
'diam' reversed gives 'MAID'.
(Other definitions for maid that I've seen before include "Serving girl" , "- - -of-all-work" , "Female domestic servant" , "Female servant - young girl" , "employee" .)