Girl, turning venal, lets expensive houses (7)
I believe the answer is:
estella
'girl' is the definition.
'turning venal lets expensive houses' is the wordplay.
'turning' says the letters should be written backwards.
'houses' indicates a hidden word (part of the clue houses the answer).
'alletse' can be found hidden inside 'venal lets expensive'.
'alletse' back-to-front is 'ESTELLA'.
(Other definitions for estella that I've seen before include "Sale let (anag) - girl's name" , "Dickensian heroine" , "girl loved by Pip" , "Pip's love (Great Expectations)" , "daughter for Abel" .)