>Well as it is a genetic problem I doubt whether the KC would allow me to show her? I understand that I cannot breed her (obviously) but I had hoped to do a bit of showing.
This is where it gets complicated! The KC is unlikely to grant permission to show her because she's had remedial dental work done - a procedure which 'alters the natural conformation of the dog'. If it hadn't been corrected you could have shown her (and always been placed last because mouth faults are viewed very seriously) but leaving it uncorrected would have been a welfare issue so you're right to have it fixed. So basically she can't be shown or bred from, but will be a superb companion.