Some times sativas can go on for what seems like forever, so it is just a personal judgement call!
I can see some of the fan leaves are fading so the time must be nearing for the chop!
I'm wondering if it will be a two part chop like your other girl?
It seems like the smart way to do such a massive haul!
I bet when you planted the seeds you never thought your crop would be so large!
Well done mate, you grew some awesome plants, soon you will get the chance to settle back and smoke them, for may be many, many months to come!