Prepare girl who’s organising competition among setters, say? (3,4)
I believe the answer is:
'competition among setters say?' is the definition.
I can't judge whether this defines the answer.
'prepare girl who's organising' is the wordplay.
'prepare' becomes 'do' (I've seen this in other clues).
'girl' becomes 'g'.
'organising' indicates anagramming the letters.
'whos' with letters rearranged gives 'show'.
Can you help me to learn more?
(Other definitions for dog show that I've seen before include "Crufts, e.g.", "Cruft's, for example".)