A noblewoman carries on so soon (7)
I believe the answer is:
already
'so soon' is the definition.
(already can mean sooner than expected)
'a noblewoman carries on' is the wordplay.
'noblewoman' becomes 'lady' (synonyms).
'carries' means one lot of letters goes inside another (inserted letters carried inside).
'on' becomes 're' ('on' can be mean 'with reference to').
'lady' enclosing 're' is 'lready'.
'a'+'lready'='ALREADY'
(Other definitions for already that I've seen before include "Previously" , "thus far" , "By the time in question" , "earlier than might have been expected" , "Even this soon" .)