Observer of timekeeper with queen (7)
I believe the answer is:
watcher
'observer' is the definition.
(I know that watcher is a type of observer)
'timekeeper with queen' is the wordplay.
'timekeeper' becomes 'watch' (watch is a kind of timekeeper).
'with' says to put letters next to each other.
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'watch'+'er'='WATCHER'
'of' acts as a link.
(Other definitions for watcher that I've seen before include "Alert observer" , "Onlooker" , "I observe" , "One who observes" , "Big Brother?" .)