Flower girl sick at heart in Romeo’s home (8)
I believe the answer is:
veronica
'flower girl' is the definition.
'Veronica' can be an answer for 'girl'. I am not certain of the 'flower' bit.
'sick at heart in romeo's home' is the wordplay.
'at heart' means to look at the middle letters.
'in' means one lot of letters goes inside another.
'romeo's home' becomes 'Verona' (Romeo and Juliet is set in Verona).
The middle of 'sick' is 'ic'.
'ic' put within 'verona' is 'VERONICA'.
(Other definitions for veronica that I've seen before include "Plant also called speedwell -- I've no car (anag)" , "Saint who wiped Christ's face on the Via Dolorosa" , "Plant of the foxglove family in a cover, oddly" , "There's a strange vain core to this plant?" , "Blue-flowered plant in a cover, oddly" .)