If you think $7 is too much, go have your group meetings somewhere else...your house maybe. No one is forcing you to meet at the shop. The shop owner is well within the bounds of 'acceptable' by any standards of business and, as an employee, you were way out of line to openly criticize her business decisions with customers.
Customers don't negotiate the prices of merchandise, why should they think they can negotiate the price of services? And space rental is a service, make no mistake about that. The rate here (NH) for using the shop's workroom...no food, no drinks, no supplies, no advice, just the room...is $5 per hour. It is paid with great gratitude in the heat of summer by many of us who don't have A/C and have to get something done on deadline.
I'm guessing the owner provided food to avoid having large amounts of messier things brought in (e.g., crock pots, etc.). If she ceases supply food, as she really should, don't be surprised if there are limits put on what users can bring in themselves. Quilt shops are not restaurants and food can do major damage to her inventory.