Girl has love in her heart for another (5)
I believe the answer is:
anona
'her heart for another' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'girl has love in' is the wordplay.
'girl' becomes 'Ana'.
'has love' becomes 'on' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'ana' going around 'on' is 'ANONA'.
Can you help me to learn more?
(Other definitions for anona that I've seen before include "Fruit" , "woman" .)