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
'bit' could be 'i' (resembles 1, a binary digit or bit) and 'i' is located in the answer.
'note' could be 're' (as in do-re-mi) and 're' is found in the answer.
The remaining letters 'ne' is a valid word which might be clued in a way I don't see.
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)" .)