Old woman, artist around in harbour (6)
I believe the answer is:
marina
'harbour' is the definition.
(marina is a type of harbour)
'old woman artist around in' is the wordplay.
'old woman' becomes 'ma' (both can mean someone's mother).
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'around' indicates putting letters inside.
'ra' going around 'in' is 'rina'.
'ma'+'rina'='MARINA'
(Other definitions for marina that I've seen before include "part of harbour?" , "Place for mooring boats" , "Airman (anag)" , "Base for pleasure boats" , "Harbour for pleasure yachts and small boats" .)