She’s a bit of a siren, note (5)
I believe the answer is:
irene
'she's' is the definition.
(I've seen this before)
'a bit of a siren note' is the wordplay.
I cannot really understand how this works, but
'note' could be 're' and 're' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for irene that I've seen before include "- - Worth, actress" , "- - Handl, actress" , "Goddess of peace - Byzantine ruler" , "Girl's name; Soames Forsyte's first wife" , "Girl's name (meaning Peace)" .)