Kelly to share peer group (10)
I believe the answer is:
generation
'peer group' is the definition.
(I've seen this before)
'kelly to share' is the wordplay.
'kelly' becomes 'gene' (I've seen this in other clues).
'to share' becomes 'ration' (ration is a kind of share).
'gene'+'ration'='GENERATION'
(Other definitions for generation that I've seen before include "peer group" , "Group born around same time" , "young" , "Everyone of same age" , "production" .)