Kendra does more work on the heavy box, and more net work is also done on the heavy box.
Explanation:
While exerting force to move the two boxes, Kendra exerts two different amounts of force (i.e. higher magnitude of force for heavier box and vice versa). On account of opposing frictional force, the boxes stop after some time.
We know Work done= F*D
∵ Where F= force applied Â
      D= Distance moved
Since the distance moved is same in both the cases hence work done would be dependent on the force applied only.
Force= m*a
Where m= mass of the box and a= acceleration
Here Mass of the heavy box would be more than the lighter box
∴ Force applied on the heavier box would be more than on the lighter box
∵Work done by heavier box would be more as compared to the lighter box.