It sounds like the FA was filling out a jumpseat form. The form has 3-parts(white, yellow, and pink). If she has been deadheading, she would have received a regular boarding pass with an assigned seat. The 50 seat RJ's have one extra FA jumpseat located on the last row of seats. It actually blocks access to the lav when in use. Therefore, after take-off, you have to move to the front jumpseat, so people can use the lav. As an employee, we would not be able to take up a revenue seat ahead of revenue passengers. I feel certain that she was jumpseating.