Wilma may be a photoperiod plant. It can happen, but should be a very low percent chance if from quality breeders.
10 weeks in is fairly safe to call it... it'll double in size once you give it 12 hours of darkness each day before it stops growing, so you may want to prune it back if you will have constraints due to tent or growing area in general... too tall, too wide.. larger than light coverage are all possible.
definitely don't go based on advertised flowering period... once buds look like normal buds, it'll be another 7-14 days?? You need a 30-60x magnier to see the trichomes. Flushing is an urban myth. the causalities given as to why you 'should' flush have all been proven bogus in studies. If you want to save a little mixing or money etc, that's fine too. This will depend on your prefered point in harvest window.. how much amber do you want?
so, maybe when you see ~5% amber in most locations you inspect, you can give a healthy plant water from that point on and probably be fine. If the canopy is not so strong, you may want to rethink that. Not specifically about your current plants, but in general. You are also in soil, so giving some ph'd water for upto 10-14 days will give the fade you typically see.