Why don't you ask your GF ... ?
She's your GF, maybe she's just trying to help you with your habits?
But, look in your Caches folders, or in Application Support folders, or look for the name of your torrent app in Preferences folders.
You can also search for files that are newly created, or modified, when you download a torrent. There's only about 10 or so different locations that I can think of, and that depends on which torrent apps you use, the torrent download settings, and what version of OS X you have.
Or, you could try a different "hobby" that's not so offensive to your GF (I suspect she keeps track of you because she likes you - think about that for a while 😀 )