Well I think her bitching on the fb page was stupid. Who the fuck cares if the hostess picks up the check and cashes you out? I worked previously as a hostess, and I would do this and get drink orders when the waiters were tied up.
The extra charge for the side isn't cool, and the devolving of the conversation to personal insults sucked, but she did mean to cause harm by the bad review.
Working in a restaurant and working in retail sucks because people complain all of the time. Usually the management sides with the customer, even when the employee did nothing wrong. The customer isn't always right.