She can, but only under the function-manager theory: she must manage an essential function at a senior level, exercise discretion over its policy and operations, and be relieved of the routine work of the function by others. Supervising two non-professional technicians does not, by itself, make the role managerial.
Build the case on the function, not the headcount
Start by defining the function in the company's own terms: the food-safety and sanitation program, its regulatory obligations, its budget, its audit exposure and its authority to stop production or hold product. Then show that the manager owns that function at a senior level, which means she reports to the plant manager or the operations director, sets the program's policies, chooses suppliers of sanitation chemicals and testing services, and is consulted on capital decisions that affect hygiene. Next, show who performs the routine work: the technicians take samples and keep records, line leads perform pre-operational checks, and a contracted laboratory runs the assays.
Finally, quantify her own time: if she spends most shifts doing verification rather than directing it, the theory weakens and the company should consider whether the role can be restructured before the petition is filed. The officer is testing discretion and seniority, not the number of names on the chart.