Pale daughter joins staff (4)
I believe the answer is:
wand
'staff' is the definition.
(I know that wand is a type of staff)
'pale daughter joins' is the wordplay.
'pale' becomes 'wan' (wan can mean pale or grey).
'daughter' becomes 'd' (genealogical abbreviation).
'joins' means one lot of letters go next to another.
'wan'+'d'='WAND'
(Other definitions for wand that I've seen before include "Conjuror's stick" , "Magical rod" , "Rod of magician or water-diviner" , "Magician's rod" , "Magician's stick" .)