While hourly rate MAY mean your hourly rate of pay, it MAY also include the "other hourly expenses" like fringe benefits. Many companies bill at an hourly rate that is more than what the actual rate of pay is to account for these extra expenses. (No, I'm not talking about making a profit over and above the employee's rate...that's a different subject)
For example, when I work on construction jobs that are covered under prevailaing wage laws and are considered "Time and Materials" jobs (also called "Cost Plus" jobs) my total hourly rate: wages, fringe benefits, social security, etc. are what the company bills the paying agency. That is my hourly rate...
HOWEVER, in the OP's cousin's case, she's probably not that deep, and is refering to her hourly pay...