Isobel is keeping packing needle (7)
I believe the answer is:
obelisk
'needle' is the definition.
(I've seen this before)
'isobel is keeping packing' is the wordplay.
'packing' says the answer is hidden in the clue.
'OBELISK' is hidden in the letters of 'isobel is keeping'.
(Other definitions for obelisk that I've seen before include "Pyramidal monument" , "Tapering monumental pillar" , "Four-sided tapering pillar" , "Tapering square pillar" , "Square stone column that tapers" .)