Party reflected my family's quality (5)
I believe the answer is:
odour
'quality' is the definition.
(odour can mean a quality or impression)
'party reflected my family's' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'reflected' says the letters should be written backwards.
'my family's' becomes 'our' (belonging to our family).
'do' reversed gives 'od'.
'od'+'our'='ODOUR'
(Other definitions for odour that I've seen before include "Regard" , "pervasive quality" , "Nasty smell" , "Pong" , "for the nose to detect" .)