One's charm is diverting the noblewoman (11)
I believe the answer is:
marchioness
'the noblewoman' is the definition.
(marchioness is a kind of noblewoman)
'one's charm is diverting' is the wordplay.
'diverting' indicates anagramming the letters (letters diverted elsewhere).
'ones'+'charm'+'is'='onescharmis'
'onescharmis' with letters rearranged gives 'MARCHIONESS'.
(Other definitions for marchioness that I've seen before include "Noble lady" , "noble wife, perhaps" , "Aristocratic lady" , "Titled woman" , "Wife of a marquis" .)