Slow growth could be for any number of reasons and is not in any way a bad thing, or not the angle of the leaves indicates a very happy plant, the color is vibrant and she looks full of vitality, whatever your doing is working fine, it's not a race, please post more accurate information, there are 9 cardinal rules to growing cannabis without knowing accurate parameters of your growing conditions one cannot help determine any issues you may be having that could be effecting rapid growth.