Scare the cat into silence and wake the roomie out of her daydream. After a couple of times, the cat may not even come back home. Just don't hold the cat outside her door while you sound the air horn.
Cats don't like certain scents, and cannot stand the smell of the Coleus Canina plant. We humans can't smell it unless we touch it. A possibility for your outside your window.
Cat Repellant Home Remedies