A girl returns with something valuable (5)
I believe the answer is:
asset
'something valuable' is the definition.
(I've seen this in another clue)
'a girl returns' is the wordplay.
'girl' becomes 'tess' ().
'returns' shows that the letters should be reversed in order.
'tess' in reverse letter order is 'sset'.
'a'+'sset'='ASSET'
'with' is the link.
(Other definitions for asset that I've seen before include "Useful thing or person" , "Plus point" , "Something valuable to have" , "Useful item" , "Tessa (anag)" .)