When Does the first official 5 leaf marijuana leaves begin to grow?

my tallest plant whcih is about 10 inches - 1 ft has grown up to its 3rd pair of fan leaves and is currently in the middle of having the fourth set grown, what set of leaves will finally make my plant look like the plant i want it to be, weed.

it should only be 6 in. get your lights closer to stop the plant stretching.