8 weeks-ish is a good rule of thumb for general hybrids/bagseeds.. But like Ryan said, it looks like they still got 3 weeks or so left, at least. Most growers will get a magnifying glass and go by the trichome production & color. Your girl still has a lot to do, in the next few weeks those hairs will turn into nice juicy buds... A simpler way for a newer grower to tell when to harvest is to look at the pistils (little white hairs), when the THC production has peaked most plants' pistils will have turned an amber/orange color (sometimes strange colors with select strains but the point is-they turn into a color that isn't white anymore).. when around 80% of them have changed will be good. waiting longer will allow more CBD production and give a "couch-lock" effect (like an Indica buzz) and taking her down a bit earlier will produce less cannabidiol, which is what I prefer but everybody is different.
Either way you go, she still needs to fatten up for a few more weeks. Also, look up a good guide on curing, it REALLY does make a huge difference, quick-drying your pot will cause THC degradation. Good luck bro.