Been growing my hair out since 4/2014 from a barbered, close cut. Not sure when I hit brastrap length as a natural (cuz I barely, if ever, length check), but when relaxed the longest was maybe armpit length because it rested comfortably on my shoulders when straightened and curled. Also, my hair was NEVER this healthy when relaxed.
I would advise an all natural newbie to tidy up their diet, drink more water, develop your own hair regimen, do as little to your hair as possible (cleanse, condition, style), consider working out (has same effect as inversion method), and take care of your scalp (don't drown your follicles in goop!). That's where the new growth comes from, so a healthy scalp promotes healthy new growth.