Pretty girl’s ring ending on pinkie (5)
I believe the answer is:
belle
'pretty girl's' is the definition.
(I've seen this in another clue)
'ring ending on pinkie' is the wordplay.
'ring' becomes 'bell' (both can mean to call on the phone).
'ending on' suggests the final letters.
The final letter of 'pinkie' is 'e'.
'bell'+'e'='BELLE'
(Other definitions for belle that I've seen before include "Lovely girl" , "Most attractive girl" , "Beautiful woman - of the ball?" , "Reigning beauty" , "Handsome lady of the Ball?" .)