Daughter leaving very much in advance (5)
I believe the answer is:
early
'in advance' is the definition.
(similar in meaning)
'daughter leaving very much' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'leaving' suggests deleting specific letters.
'very much' becomes 'dearly' (eg to pay dearly is to pay very much).
'dearly' with 'd' removed is 'EARLY'.
(Other definitions for early that I've seen before include "Before appointed time" , "Before the expected time" , "New-season" , "In good time" , "Forward" .)