When is this plant ready to harvest?

At least one months.

nope you have got to this point don't ruin it :) 3 weeks minimum ignore all the trike talk on your first and just concentrate on other signs you will get a much better yield the longer you let her flower and the longer she flowers the more trichomes will mature and develop. my opinion anyway I look for loads of signs before cropping and most of the pistils have to be brown and the strain hasto smell like its ready in my opinion. but hey your plant your rules do what you want :)

it all depends on what effect you are hoping for from your weed. Milky trichomes = energetic high, amber-coloured trichomes = physical high. a bit of both = head and body high. just check your trichomes for this what i can see at your pictures, she could be ready to harvest. looks like a good mix of milky and amber coloured trichomes.