You should also get some Fox Farm Nutes and follow the instructions for feeding on the chart (the chart is available online or from the distributer) but modifiy it for the stages of flowering your in. Like right now I would be giving her (hopefully) big bloom and growbig for the vegitve stage until the first signs of sexing.

You can find them online and get both liquid and granular form and mix them at feeding acording to the chart.

Also when you start getting alternating nodes look very closely at the the part where the plant has formed a secondary branch and where pre-flowers will form. A Female will have 1 ball forming with a small hair sticking out of the middle on both sides of the node, a Male will have more than one ball with no hairs sticking out also on both sides of the node. You will need a magnifying glass to do this. These pre-flowers are very tiny and hard to see with the naked eye.

By the way looks like your off to a good start your plant looks healthy.

JG