My lady learned a great drill from the wakeboard camp regarding progressive edge.
Let the rope all the way out. start in the trough of the wake, and cut out about 15 feet.
When you finish your cut out, watch the shoreline you are facing, flatten the board out and let the rope regain its tension while riding flat and straight for a count of 3.
look back across the wake, lean back against the rope, and begin a SLOW cut towards the wake with your knees bent at almost 45 degrees.
continue looking across the wake during the entire cut, and focus on staying on the same line all the way across, while absorbing the wake with your knees.
continue to cut at the same angle away from the wake, and do the same thing toeside.
once you are able to make it back and forth in a straight line, you have the skills of a progressive edge. all you have to do is make the same cut, and stand tall at the wake. if your body and board remain at the same position it was in for the no air wake crossings, and you add a small push instead of absorbing the wake, you will pop right up into the air.