Nothing by daughter in gallery so far (2,4)
I believe the answer is:
to date
'so far' is the definition.
(I've seen this in another clue)
'nothing by daughter in gallery' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'by' means one lot of letters go next to another.
'daughter' becomes 'd' (genealogical abbreviation).
'in' is an insertion indicator.
'gallery' becomes 'tate' (Tate Modern, Tate Britain etc).
'o'+'d'='od'
'od' inserted within 'tate' is 'TO DATE'.
(Other definitions for to date that I've seen before include "Until this point in time" , "Up to the present time (2.4)" , "Up to this time - check calendar" , "up to the present day" , "Amorous American's aim," .)