Sarah operating in hairdressing establishment? (5)
I believe the answer is:
salon
'hairdressing establishment?' is the definition.
(I've seen this before)
'sarah operating' is the wordplay.
'sarah' becomes 'sal' (Sally is a common pet form of Sarah).
'operating' becomes 'on' (I've seen this in other clues).
'sal'+'on'='SALON'
'in' acts as a link.
(Other definitions for salon that I've seen before include "Elegant room - for hairdresser?" , "Hairdresser's premises" , "Place of business for eg beautician" , "Beautician's establishment" , "Call loudly" .)