HMMM...as far as being done, not at this point. But, if I were forced to make a guess...I would say 3-4 weeks. But, my guess may not be worth a shit. I do feel there are more indicators of maturity than trichomes. Pistils, turpenes, calendar age, amount of leaf dump...and growerz choice. In fact, some strains will show 'amber' trichomes at a very young age. and could give the grower a false impression of maturity level. I go by the tried and true method of...it's my grow and I'll chop if I want too.
What I am more concerned about is the pretty severe N toxicity she is showing. She is at the stage where she is getting fatter by the minute and absorbing all the medium has to offer. If the N issue is not dealt with ASAP you will lose a lot of flavor and taste of final product. You will have weed that tastes 'green'. Get some opinions on the condition and curative measures before taking a plan of action. IMHO...if this were my grow I would flush pretty darn well...let her get good and dry and than resume bloom feeding at 1/2 strength. But, again that's just what I would do.