Sweetheart from Florida with armlet oddly selected (5)
I believe the answer is:
flame
'sweetheart' is the definition.
(I've seen this before)
'florida with armlet oddly selected' is the wordplay.
'florida' becomes 'fl' (abbreviation for Florida).
'with' means one lot of letters go next to another.
'oddly selected' indicates alternate letters.
The alternating letters of 'armlet' are 'ame'.
'fl'+'ame'='FLAME'
'from' is the link.
(Other definitions for flame that I've seen before include "Ignited gas" , "Burner -- passion" , "Hot" , "Orange-red; set alight" , "Orange-red colour" .)