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 another word for mother or mum).
'has' is an insertion indicator.
'a strange' is an anagram indicator.
'air' with letters rearranged 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" .)