Queen after time is a charmer (7)

'a charmer' is the definition.
(someone casting spells)

'queen after time' is the wordplay.
I cannot quite see how this works, but
'queen' could be 'er' (abbreviation for Elizabeth Regina) and 'er' is located in the answer.
'time' could be 'spell' (both can mean a short period of time) and 'spell' is found within the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).

'is' acts as a link.

Can you help me to learn more?