The 50-year-old woman is a repatriated Fijian citizen who returned from India on 1 July.
She is the wife of one of the earlier announced border quarantine cases from the same flight.
When her husband tested positive they were both moved from quarantine to an isolation facility at Lautoka Hospital.
She had tested negative during a first round of testing but tested positive after a second round.
The new case brings to a total of nine border quarantine cases announced since 6 July, all repatriated citizens from the same flight.
The remain passengers have been cleared of the coronavirus.