Unfortunately, you have a sativa dominant strain so your flower time should extend for 10+ weeks. Harvesting now would be a shame.
In your position, I would start by examining every single flower for sickness. Remove any that you're unsure about. Cut off fan leaves where the foliage is dense to increase airflow. Get a couple fans rolling to circulate as much air as possible. An inline fan would be a great addition if you don't have one. Direct the air out of the tent and open up a vent or two for the fresh air to pull in from. A nice, dry environment with fresh air is your best chance to save her.