Plant looks great. Here's a great tip, so you'll easily see for yourself when it's ready. During the next weeks trichoms (the crystals on the bud) will start getting bigger. In the beginning they will be clear and shiny. While the plant is under lights take a good look - you'll see them shining like small diamonds. But as the trichomes mature they will get milky white (telling you they are full of THC and ready for harvest). You'll easily see that the "diamond shine" will stop and the trichomes have turned more pale white. Now it's time to harvest.
Don't take the "expected harvest time" too serious as many (most) strains are hybrids creating different phenotypes. From one packet of seeds one plant might be done after 50 days while another needs 110 days. Hope this helps you a bit.