One of the family Grannie certainly embraces (5)
I believe the answer is:
niece
'one of the family' is the definition.
(I've seen this in another clue)
'grannie certainly embraces' is the wordplay.
'embraces' indicates a hidden word (I've seen 'embraced' mean this).
'NIECE' is hidden within 'grannie certainly'.
(Other definitions for niece that I've seen before include "[PRIEST'S] daughter?" , "Son's cousin" , "Brother's daughter" , "Kinswoman" , "Daughter of a sibling" .)