Answer:
Here the mistake is that she drew a circle from the point A to intersect the line rather the drawing arcs from the point C
The next another circle was drawn from the point of the intersection of the first circle and the intersection of both circles was used to draw the perpendicular at the midpoint of the intersection of both circles.
Explanation:
To construct a line perpendicular to another line through a point the following steps are required
1) From the point, with the compass, C draw to intersect the line at points A and B
2) From A and B with the compass made wider, draw arcs above and below the line to intersect each other
3) With the straight edge Draw a line passing through the intersections of the arcs drawn from A and B and extend the line to pass through the point C
The line constructed above is the perpendicular to the line l passing through the point C.