Female stops collecting silver pieces of little value (3,4)
I believe the answer is:
fag ends
'pieces of little value' is the definition.
(fag ends can mean anything of little value)
'female stops collecting silver' is the wordplay.
'female' becomes 'f' (abbreviation).
'stops' becomes 'ends' ('end' can be a synonym of 'stop').
'collecting' means one lot of letters goes inside another.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'f'+'ends'='fends'
'fends' enclosing 'ag' is 'FAG-ENDS'.
(Another definition for fag ends that I've seen is " Discarded parts of cigarettes".)