$100 in a 12 hour shift as a server is not good. Although would be important to know how busy that IHOP is and if she's getting 12 hour shifts on good money days or not.
Yeah... as someone who has been a line cook for 13 years, if you have to work more than 3 hours (assuming the "a lot of tables" part is true) to make $100+ in the front of house then you suck at your job.