She wants some more money (4)
'she' is the definition.
'some more money' is the wordplay.
'some more' becomes 'mol' (I can't justify this - if you can you should give a lot more credence to this answer).
'money' becomes 'l' (L can mean 'pounds').
'wants' acts as a link.
Can you help me to learn more?
(Other definitions for moll that I've seen before include "Gangster's female companion", "Gangster's girlfriend", "Book by Defoe", "Hood's girl", "Gangster's girl".)