question about chronic pain

My roommate has chronic pain. She has arthritis in her whole body from a diving board accident that happened when she was young. She comes home every night and pretty much zones in front of the tv. It's frustrating for me because, from my point of view, her actions are stating she thinks all the shared space is hers. I do have other reasons to think she's territoriality aggressive, but I'm wondering how much this action could be driven by her pain.

1/2 way there

I hit the halfway mark on word count for NaNo today and was challenged with this prompt: 
Take this dare from 10th grade Young Writers Program participant Janie-Ray: "Your character is stranded in the middle of the zombie apocalypse. How would they survive?"

Yeah, I'm writing Buffy fanfic. I think my characters would be fine. ;-)