If you only watered them with no fertz just water for the last week atleast or even longer then yea I'd say it's time to chop those baby's down and get to trimming, safe to say it's harvest time for the girls I wouldn't worry bout any problems growing wize from here on out, jus focus on the trimming, drying, curing, burping the jars bout 3 to 4 times a day for a few weeks then finally smoking them,
I find to have a harvest mainly and most deffenty involves the growing but also the harvest and the time you spend with drying curing and how you handle your buds and store them when done, also the environment the buds are drying in, with the perfect method and environment a harvest can be amazing come smoking time!!
Good luck and congrats on the girls!!