A lack of money away from home? (3,2)
I believe the answer is:
not in
'away from home?' is the definition.
('she's not in' means 'she's not home')
'a lack of money' is the wordplay.
'a lack of' becomes 'no' (lack of money is no money).
'money' becomes 'tin' (old-fashioned slang term for money).
'no'+'tin'='NOT IN'
(Other definitions for not in that I've seen before include "Out or away, house empty" , "ie Out" .)