well if you look at the first pic, the bud is mostly white pistils and you can tell she is far from done. that bud needs atleast 3 weeks till its done. the second picture looks close to ready, you notice the calyxes(what the pistils come out of) are swollen and huge on that nug and the pistils do no dominate. it depends on the strain how much they swell but they usually get the same aspect(big swollen calyxes compared to calyxes during the bud growth). Id say wait 3 weeks, the longer they go the more potent but more stoney, if you want a more up high(cerebral) you can think about chpping sooner.
looking at those pics i would give the 2 pics in post #27 and the 2nd pic of post#28 about a week or 10 days. the 1st pic of 28th post looks like it could go 3 weeks. this is kinda not the best organized explanation. did you get the idea?
btw the first 3 pics i mentioned look delicious, what strain is that? maybe post a pic of each strains main cola and i can help you out. and if your going to harvest at different times then i wouldnt worry too much about flushing the earlier girls cus that means u have to flush the latter ones if they are in the same system.
is this your 1sr grow? you seem to have great equipment, did you use to grow tomatoes?