Something lucky in grandma's cottage (6)
I believe the answer is:
mascot
'something lucky' is the definition.
(I know this)
'in grandma's cottage' is the wordplay.
'in' indicates a hidden word.
'MASCOT' is hidden in the letters of 'grandmas cottage'.
(Other definitions for mascot that I've seen before include "that's charming?" , "Lucky talisman" , "One is lucky" , "Lucky person" , "Team's good luck bringer" .)