Only daughter, say, brought up having kittens? (2,4)
I believe the answer is:
on edge
'kittens?' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'only daughter say brought up' is the wordplay.
'only' becomes 'one' (synonyms).
'daughter' becomes 'd' (genealogical abbreviation).
'say' becomes 'eg' (both can mean 'for example').
'brought up' says the letters should be written in reverse (in a down clue, letters go up).
'eg' reversed gives 'ge'.
'one'+'d'+'ge'='ON EDGE'
'having' is the link.
Can you help me to learn more?
(Other definitions for on edge that I've seen before include "Anxious, nervy" , "Nervous and tense - close to cliff?" , "Fidgety, nervous" , "Under stress" , "Cliff-top walker may be" .)