Aidan's new girl, a change from Nadia (5)
I believe the answer is:
diana
'aidan's new girl a change' is the definition.
I can't judge whether this defines the answer.
'from nadia' is the wordplay.
'from' indicates anagramming the letters (from the letters).
'nadia' is an anagram of 'DIANA'.
Can you help me to learn more?
(Other definitions for diana that I've seen before include "female" , "Woman" , "Roman goddess of the hunt, or tragic English princess" , "Girl" , "Roman goddess of the moon and hunting" .)