In this section the following words have the meanings indicated. “Employee” means an individual who: is employed by an employer to work full–time or part–time; has worked for the employer for the last 12 months; and has worked for at least 1,250 hours during the last 12 months. “Employer” means: a person that: employs 50 or more individuals; and is engaged in a business, industry, profession, trade, or other enterprise in the State; the State and its units; a county and its units; or a municipal government in the State. “Immediate family member” means a spouse, parent, stepparent, child, stepchild, or sibling. An employee may take leave from work on the day that an immediate family member of the employee is leaving for, or returning from, active duty outside the United States as a member of the uniformed services. An employer may not require an employee to use compensatory, sick, or vacation leave when taking leave under this section. An employer may require an employee requesting leave under this section to submit proof to the employer verifying that the leave is being taken in accordance with subsection (b) of this section.