She called up, Charlie being missing (5)

I believe the answer is:

della

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'she' is the definition.

'called up charlie being missing' is the wordplay.
'DELLA' is hidden back-to-front in amongst the letters.
But, I am uncertain how this is indicated.

Can you help me to learn more?

(Another definition for della that I've seen is " - - Street (Perry Mason)".)

I've seen this clue in the Evening Standard.

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