When the trichomes ratio is closed to the one you are targetting. it means you needs a x40 magnifier to take a look at the trichomes aka the frost on the buds and the leaves. If you can't/don't want to get a magnifier then check the breeders flowering time recommendation and add a week or 2 because they are all giving you the shortest value and they are testing the plant in the best controlled environement possible at a professionel level so far from what we can do at home so we may have a longer flowering period.
That said , by her shape she is not looking ready to me and she is dark green like a plant that is experimenting a Nitrogen excess so if I'm right the N excess will extend the flowering period , so N excess + 1 or 2 more weeks = at least 3 more weeks to go so you can flush in 2 weeks from now ( according to me )