In Step 2, Lara did not ensure that the second diamter was perpendicualr to the first diameter she drew.
The correct steps should be:
Step 1: Use the straightedge to draw a diameter of the circle. Label the points at which the diameter touches the circle as A and B.
Step 2: Draw a second diameter perpendicular to the first diameter. Label the points at which the second diameter touches the circle as C and D.
Step 3: Join the end points of the two diameters to form a square.