Charm of mummy’s bed (6)
I believe the answer is:
mascot
'charm' is the definition.
(I've seen this before)
'mummy's bed' is the wordplay.
'mummy's' becomes 'mas' ('ma' can be a synonym of 'mummy').
'bed' becomes 'cot' (cot is a kind of bed).
'mas'+'cot'='MASCOT'
'of' is the link.
(Other definitions for mascot that I've seen before include "Thing believed to bring good luck to its owner or team" , "It's adopted by a team as a symbolic figure" , "good luck charm required" , "One for good luck" , ".Person or thing believed to bring good luck" .)