They get taller in the sense that the rosette compounds on itself (if this makes sense) and you have a "semi-tall" plant full of leaves. It won't get tall like 'Laurentii' tall, so I don't think 3' is correct.
This is not my picture, but this sort of "explains" better with regards to height.
Checkout the plant on the left.
I believe hahnii and bird's nest are both synonyms for this type of 'Snake Plant'
