Sometimes she just take a while, make sure there is jonlight leaks.
Cannabis will not stop flowering if the lights are turned on for a few minutes once or twice during the 2-month-long flowering cycle. If a light is turned on for 5 to 30 minutes—long enough to disrupt the dark period—on 3 to 5 consecutive nights, plants will start to revert to vegetative growth.
Less than one half of one foot-candle of light (0.1ppfd) from sunlight will prevent cannabis from flowering. That is a little more light than is reflected by a full moon on a clear night. Well-bred indica-dominant plants will revert within three days. Sativa-dominant plants take four to five days to revert to vegetative growth. Once they start to revegetate, it can take from four to six additional weeks to induce flowering again!