GrowCNanswered grow question 4 years ago Flowering time is always a range. Usually 4-6 weeks but I don't panic until 8 weeks if they haven't started to flower. Luckily it looks like at least one picture looks like the start of flowering.
As for yield I think you will do OK. The first Critical Purple I grew produced over 50 grams (about 2 oz) each. I gave more light to force a more compact plant and did LST to keep as many flowering sites at the same height on top, sort of like sea of green method and was rewarded with many, big buds on top. With your grow I think you'll be faced with a decision. I'm sure you will get a good number buds on top but you'll have to decide if you keep the others that develop lower. You can trim the lower ones so the plant focuses on the top buds or just let everything grow and get some popcorn nugs.