Are we interpreting our workweeks incorrectly, and in doing so, creating FLSA worries?

Q: “I am attempting to understand the FLSA rules on overtime. I have an employee who works at a reception counter greeting guests, directing them to their stations, checking them in and out. This employee is an hourly employee making $13.50/hour, working between 35-45 hours per week. Is she entitled to overtime over 40 hours per week? Also, we get paid on the 15th and end of the month and our workweek runs from Sunday to Saturday. This past pay period, we had three weeks, as follows: Week 1: June 1 - June 2 Week 2: June 3 - June 9 Week 3: June 10 - 15 “With the exception of week two, this employee did not have a chance to work a full week. In this situation, I feel like I am not looking at the workweek correctly...?” – Katie, Louisiana