Saying little, Nicola’s mad about Charlie (7)
I believe the answer is:
laconic
'saying little' is the definition.
(I've seen this before)
'nicola's mad about charlie' is the wordplay.
'mad' is an anagram indicator.
'about' indicates putting letters inside.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'nicola' with letters rearranged gives 'laonic'.
'laonic' going around 'c' is 'LACONIC'.
(Other definitions for laconic that I've seen before include "Saying little" , "Conical (anag) - pithy" , "'Curt, terse (7)'" , "not saying much" , "Concise - terse" .)