Hey flynfish, looking good. Keep doing what your doing and remember that overwatering is the biggest mistake newer growers make-let your cups get kinda dry inbetween waterings and you will have faster root development and a happy plant.
As far as LST goes- I would recommend starting once you have at least a few nodes. I would let her grow for another 7-14 days and get a little more established, she's just a baby at this point
. Remember that bending the top down is going to make all the side branches reach up, so it's up to you and exactly what you want to do. I like to wait until my plant is about 4-6" tall and has at least 4 or 5 nodes, then I tie the main tip down as far as I can. If you wait too long and the main stem gets kinda hard, it's ok to bend or 'super crop' it too.
Hope this helps, keep up the good work.