Children's game introduced to adult female in later years (6)
I believe the answer is:
dotage
'later years' is the definition.
'children's game introduced to adult female' is the wordplay.
'children's game' becomes 'tag' (playground game).
'introduced to' is an insertion indicator.
'adult female' becomes 'doe' (female deer).
'tag' going into 'doe' is 'DOTAGE'.
'in' acts as a link.
(Other definitions for dotage that I've seen before include "decrepitude" , "Foolish infatuation" , "period of twilight" , "Aged to? (anag)" , "Senile years" .)