As for the height, it sounds like they are NOT stretching for the light, which is a great thing...so not to worry. I also have a feeling that what you have are probably an indica strain, which grow short and bushy. I am growing an indica dominant strain that is over 2 months old and just over 1 foot, but bushy as hell. On the other hand, I also am growing a sativa dominant strain (white widow) that is just over 3 months old and is over 6 foot.

GTD