Is 3,361.63 wings a day really that much for a wings restaurant to sell?
Wingstop charges basically $1 per wing if you by 10 at a time. So you're talking about $3,361.63 of revenue a day from the wings. I think that's good revenue. Especially when you talk about adding drinks to it and maybe fries or whatever, but you're talking under 2.5M of revenue over two years. If you aren't stealing the wings, basically $1.5M of that $2.5M is going to wings. So you have $500k a year to pay rent, utilities, insurance, staff, oil to fry in, cutlery, etc. and if yu're not stealing the wings to begin with, you've got to pay ~$1.5M for the wings, so you basically have $500k a year of revenue to pay all that (or really you have $500k plus whatever profit you make on drinks and fries or whatever), but if that was an unreasonably high amount of wings to sell, I don't think you'd ever see any wings restaurants get opened up.
ETA: And that assumes whoever she was selling to only had one location (or that she was only selling to one buyer). Hell, she may not have had to sell at all. Could have been their supplier paying her to put in the orders through the school and then he/she was selling for cash off the truck to multiple mom and pop restaurants.