Her mother has a strange air (5)
I believe the answer is:
maria
'her' is the definition.
(I've seen this before)
'mother has a strange air' is the wordplay.
'mother' becomes 'ma' (ma is a kind of mother).
'has' is an insertion indicator.
'a strange' is an anagram indicator.
'air' anagrammed gives 'ari'.
'ma' going around 'ari' is 'MARIA'.
(Other definitions for maria that I've seen before include "Black --, police van" , "Dark planes on the moon; girl's name" , "Italian Mary" , "West Side Story girl" , "Lady" .)