For a Yankee, AO is probably similar to what USO is for a Finn, matches start in early evening and last until the morning. How I watch the USO is that I start watching first matches of the day and continue until I gotta go to bed. And if I lived in da States, I'd probably do that with AO. But AO SFs and F are evening matches unlike in USO; I'd probably change my sleeping rhythm before semis so that I go to bed early and wake up for those matches.
But how not to disturb your roommate? I once shared a flat with another guy but we luckily had different rooms so at least watching couldn't disturb him, and he never complained about my alarm clock ringing in the middle of the night. But if you're watching TV/computer screen in the same room, that can be disturbing for some people. But if it really disturbed her, it'd show she's a tennis fan also, and if she didn't care about tennis, it wouldn't disturb her. But if she ain't a tennis fan, I'd be more worried about if she'd prevent going to sleep early. But if she didn't allow you to sleep in early evenings, don't then let her sleeep in early mornings.
Book a hotel room for your roommate and pay for her to stay there. Problem solved.
I'd rather book the hotel room for myself.