This sounds like a level of anxiety that should probably be addressed by a therapist, though I don't know how comfortable you'd be suggesting that or whether she has the resources and/or desire to do that NBA Live Coins.
I know what you're asking is very simple, but she may get very real, physical, visceral reactions to what's going on. However, you may try putting up a temporary, folding divider between the living room and the kitchen. It could give her enough privacy to keep away the anxious feelings while giving you some space in your own home to enjoy.
I suspect she has disordered eating and a very difficult relationship with food, and having people around while she's cooking or eating is a giant trigger for her. Now, this is not your problem--she needs to work on this, because it's a her problem.
If a schedule would help, and she'd stick to it, set up a schedule, but she needs to eat in her room or something, because demanding that her roommates stay out of the kitchen for 3+ hours every night is unreasonable.
This insanity brings back a lot of memories for me. Just do what you're doing and ignore her.