Yeah if she's a sativa I say give her a good.... she will double or triple in size during flowering as other folks have said. Start early, and write down your heights when you flipped, and finishing heights for future reference - get to know your strain.
Also, I have found with sativas that you should really take off ALOT of the bottom branches... alot of people do the bottom 1\3 of the plant... I will take off even more... and leave the branch structure that is most exposed to the light, they will concentrate their energy to the area which will yield you the most.
Also, measure how much space your plants take up and adjust your plant total accordingly for the next run. Just because you have limited height doesn't mean you have to flower too early and not fill your canopy... you just need to figure out how many of those ladies you can fit in your area at the size in which they end up after flowering for a few months.