My approach here, which I have pursued a few times before is to draw one half of the pose (firstly her left side from the front) then to move my easel to the other side of the model and then to draw her left side from the back. Two more moves, back and forth, is accompanied by a morphing process in which a degree of overlap and interpenetration of the two halves takes place. The outcome is uncertain. In fact I believe it is quite a gamble. How much I am in control of the content of the morphing process I don't know. The outcome is clearly a drawing of a seated model, comfortably relaxed, arms and hands resting on legs. But then the beholder becomes aware that something is not quite as it should. Attention is grabbed. One then just has to try and sort out what is in fact happening.