Q. We classified our janitorial supervisor as an
A. Probably not. First, look at her job description (every employee should have one) and determine whether she could fit into one of the exemption categories. She probably doesn't meet the “executive” exemption—which may be the category you believe she fits in since she can hire and fire—because her primary duty doesn't involve the of an enterprise or a department.
Your next best hope is that she'd be considered an exempt “administrative” employee if her primary duty is performing nonmanual work directly related to management or general business operations and she regularly uses independent judgment. But the question becomes: Is her primary duty nonmanual work? Probably not if she spends most of her time cleaning. The scale might tip the other way if she spends considerable time on nonmanual management tasks like ordering supplies, educating other janitors and directing their work.
Again, all these things should be considered in her job description.