Sister is in a whirl with love tales (7)
I believe the answer is:
stories
'tales' is the definition.
(a tale is a story)
'sister is in a whirl with love' is the wordplay.
'is in a whirl with' indicates anagramming the letters.
'love' becomes 'o' (love means zero in tennis).
'sister' with its letters mixed up with 'o' can make 'STORIES'.
(Other definitions for stories that I've seen before include "For example, scoops" , "Floors" , "House sections" , "Lies" , "Accounts" .)