A girl called Heather (5)
I believe the answer is:
erica
This could be a double definition.
'a girl' is the first definition.
(I've seen this before)
'called heather' is the second definition.
'erica' can be an answer for 'heather' (the plant genus Erica includes heather plants). I am not sure about the 'called' bit.
Can you help me to learn more?
(Other definitions for erica that I've seen before include "Heather, for instance" , "Girl's name - I care (anag)" , "Girl - heather" , "Heathland shrub; girl's name" , "Moorland plant, girl's name" .)