I'm not "scheduled for 8 hour shifts" per se, but it's obvious whenever my PT sup tells me that I'm coming in to work before 5pm that I AM going to be working well over 5 hours. Yesterday I took a break, and my PT sup was pretty nice about it. So, the situation is definitely resolved -- It's just that they should have told me when we talked about me sitting on that nook. We got into a "heated discussion" over it. I was not arguing with her, only standing up for myself.
I didn't insult her. I just said that I NEEDED to sit down, and explained why. I am working more than everyone other than the PT sups there, and I was not going to accept her saying "Do you see anyone else sitting?" I worked way harder than all of them so I sincerely didn't care if they were sitting or not. I NEEDED to give my legs a break or I was going to be useless the next day. She finally told me to take a break instead and that's what I've been doing since then.
She was definitely short and rude in her responses which were unnecessary, but I'm moving on. I know now that she's not as cool as I thought she was before. No big deal. Not like I was going to try to hang out with her or anything outside of work.