[NC] question about FMLA

Location: North Carolina

Hello,

My sister is having a procedure in November. Paid FMLA leave has already been approved for three weeks. Here is where the question lies:

She is aware that she must return to work for 30 days after FMLA ends or else the company can (but may not choose to, depending) legally recoup what they paid in insurance premiums for the time spent on leave. Could someone clarify, does that just mean the cost the company pays for the insurance benefits during that time?

Say my sister gets about 170/paycheck deducted and the company pays about 400/paycheck (purely made up numbers for anyonymity) for her insurance. For those three weeks, our understanding is that the company could legally recoup ~600 dollars (400x1.5 pay periods) for the insurance premiums they paid. Is this correct? Employee handbook says nothing specific to contradict or confirm this.

Or can they ask her to pay that plus the cost insurance covered for the procedure? Because if need be, if she needs to resign AFTER leave is through, we can repay the 600. We cannot repay the roughly 70,000 estimated for the procedure.

Will happily respond with other relevant info as needed.

Thanks.