I used to eat 4-5k calories a day, but it wasn't clean food. When i was big into powerlifting i would eat as much as possible to gain weight. After a heavy workout me and a couple other guys would go to Outback Steakhouse and eat so much it was retarded. Based on what i knew about the menu, we were eating about 3-4k calories in a little over an hour. Lots of garbage though and plenty of cheesecake.

I don't see how you can sustain that, it made you so sluggish for hours. I was watching the strongman competitors on youtube try to eat 20-30k in one day, even Thor had problems doing it.
We only did this on weekends, during the week i doubt i ate more than 4k calories, but i ate lots of breads, cheese, a few gallons of milk per week, breakfast sandwiches, etc. Hell i could eat 2 Freschetta frozen pizzas by myself, just not every day. I don't think you can really clear 4-5k a day for extended periods of time unless you have a ridiculous metabolism. I remember they said Phelps ate like 10k per day, but it was like pizza and stuff?
I used to work with a guy who was one of the top Ironman competitors in Texas, he ate more than anyone i ever saw and he was lean as hell. I would think he might have hit 5-6k a day; he'd eat 2-3 times more per meal than i did and he ate every 3-4 hours. But he trained like 3 times a day, he swam every morning, jogged during lunch and would ride a stationary bike for hours after work. We went to the same gym, when i got there he'd be on bike a good 30 minutes already, i'd lift weights for about a hour and when i left he'd still be on the bike, completely balls out full speed. He was literally a machine, traveled all over the world to compete.
Today i eat very clean and might hit 2500 a day, but i'm just trying to stay in shape and be relatively lean. When i want to cut a few pounds i just drop down to ~1800 and do cardio 3 days a week.
This chick simply upped the dosage and probably added calories to her diet, but i serious doubt someone her size could eat for than 5k a day for extended periods of time.