Hi, as you say by yourself, This Girl will probably need 9-10 weeks. Pistils dicloloring that is " normal". To see if a plant is ready you got to inspect the whole Plant. Near the end clors of leaves are changin to autumncolors, red, yellow, brow.. your Girl looks fresh green. Trichomes are maturting in stages, first cler then cloudy, and in the end amber. Your goal should be to have full cloudy ( mature) trichomes, and maybe some amber inbetween.
Besides that your Girls look great. You are more than halfway through Flower. In this stage watch out for Humidity, that its not to high. same to Temperarure and Light. Girls need is warm but not to hot, and light yes but not to much - You can feed them Molasses. so the microbaterias in your Growmedium were fed. Those help the plant to absorb Nutrients.
Happy Gardening.. and Patience