Why does "just now" appear in this sentence with a past continuous tense? What does it mean here?
Who was Clara texting just now?

Question

Answer

'just now' here means 'just a moment ago'.
 It's the immediate past - a few seconds or a few minutes ago.

Who was she texting a few minutes ago.
The advantage of saying 'just now' is we don't have to specify the exact time ago it was - maybe it was minutes ago, maybe sooner.

Answer

'Just now' = time reference relating to the immediate past.  Clara recently finished texting someone.

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