Shy daughter has condition suitable to involve study (9)
I believe the answer is:
diffident
'shy' is the definition.
(synonyms)
'daughter has condition suitable to involve study' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'has condition' becomes 'if' (I can't explain this - if you can you should believe this answer much more).
'suitable' becomes 'fit' (similar in meaning).
'to involve' is an insertion indicator (inserted letters get involved).
'study' becomes 'den' (term for a study or office).
'fit' placed around 'den' is 'fident'.
'd'+'if'+'fident'='DIFFIDENT'
(Other definitions for diffident that I've seen before include "Bashful" , "Shy" , "Lacking self-confidence" , "Reluctant to come forward" , "Timid" .)