She's soft and noble (5)
I believe the answer is:
pearl
'she's' is the definition.
'soft and noble' is the wordplay.
'soft' becomes 'p' (musical abbreviation for piano, 'soft').
'and' says to put letters next to each other.
'noble' becomes 'earl' (earl is a kind of noble).
'p'+'earl'='PEARL'
(Other definitions for pearl that I've seen before include "Precious gem" , "Small type" , "Gem from a bivalve" , "prized example" , "piece of wisdom" .)