Our nanny got covid . tested negative on day 9 and positive on day 10 . can she end quarantine?

The antigen test (+) is reliable than (-) but it can still be (+) for longer than 2 weeks. If she was symptomatic, better if she stays in quarantine for 2 weeks, just to be on the safe side for your family, no need to test after 2 weeks. If she was asymptomatic, she can end the quarantine.

The PCR test may continue to be positive for weeks. The infection may or may not be contagious after 14 days. The positive test should be considered confirmation of COVID-19. She should quarantine for at least 10 more days. She may return to work once negative and without symptoms at that point. The children should be vaccinated as eligible