Sister of Laertes (7)
I believe the answer is:
ophelia
'sister of laertes' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ophelia that I've seen before include "Character in Hamlet" , "she's a part to play" , "Sister of Laertes in Hamlet" , "She loved Hamlet" , "Shakespearean character" .)