Girl nuts about stealing cattle (8)
I believe the answer is:
rustling
'stealing cattle' is the definition.
(I've seen this before)
'girl nuts about' is the wordplay.
'about' indicates anagramming the letters.
'girl'+'nuts'='girlnuts'
'girlnuts' with letters rearranged gives 'RUSTLING'.
(Other definitions for rustling that I've seen before include "crime in the Wild West" , "Light noise, like leaves blowing in the wind" , "Stealing cattle" , "Gentle sound" , "Cattle theft" .)