I've just looked at your pics. This plant will be ready (Indica) by last week of September. Its normal for fan leaves to yellow during flowering as the plant uses its nutrients. If the plant is in a pot then you are going to have to supply some nutrients to maximize bud production. As for height, your plant will stretch once flowering starts (as you said, mid-August in CH) but by now it will not stretch anymore as bud production commences.
You can tell when its ready when the trichomes become cloudy. Watch for this carefully towards end -Sept by monitoring the trichomes with a x30 hand-held microscope. If you don't know what I'm talking about, then just pull your plant when the pistils (white hairs) begin to turn brown/red.