She is always mature perhaps - but certainly no dame! (4)
I believe the answer is:
edna
'dame' is the definition.
(comedy character Dame Edna Everage)
'she is always mature perhaps but certainly no' is the wordplay.
I cannot really understand how this works, but
'no' could be 'n' (common abbreviation y/n) and 'n' is found in the answer.
'she' could be 'eda' and 'eda' is present in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for edna that I've seen before include "Female Dane, oddly" , "Barry Humphries' Dame" , "Prolific Irish woman novelist . . . . O'Brien" , "Girl for Dane" , "Female name" .)