Like a couple week ? it’s on week 8/9 now though
Estimates of when plants will mature are just estimates, and many breeders provide estimates that are at best optimistic and unlikely with most grows. Bottom line is, predictions be damned, the plant chooses when it is done. Yours is very healthy, and looks to me to be at least a couple weeks short of done.
As to flushing, some growers do, some don't, I don't. I don't see any likely advantage to starving a plant as it finishes up, but lots of others disagree. One of the main problems is that, IMO, it is impossible to predict with accuracy when a plant is going to finish a week or two ahead of time. Some take their sweet bloody time even when you think they are close to done, others finish off in an amazing hurry. My CBD girls in my current RotBlock test have gone from no amber pistils to nearly all amber in about four or so days, much to my surprise. Had I guessed earlier this week when they might be ready, I would have been dead wrong by at least a week and a half (but hey, I could still be wrong, again). The trichomes speak, and to see them you need at least a loupe so you can check them for cloudiness and ambering. You can also get a usb or wifi microscope that gets you in really close for not much more than the price of a decent loupe.
Nice plant mate, don't chop her too early.