Mother identifies servants (5)
I believe the answer is:
maids
'servants' is the definition.
(maid is a kind of servant)
'mother identifies' is the wordplay.
'mother' becomes 'ma' (Ma is another word for mother or mum).
'identifies' becomes 'ids' (ID can mean to identify).
'ma'+'ids'='MAIDS'
(Other definitions for maids that I've seen before include "Getting women in service" , "girls!" , "Female domestic servants" , "Lasses" , "Female domestics" .)