To determine if \( \overline{NO} \) is a constructed copy of \( \overline{PQ} \), Thuy needs to compare the lengths of the segments directly. The correct response would be:
She must measure the distance from point N to point O using a compass and place the compass on point P to see if point Q is the same distance.
This way, Thuy can confirm if the lengths of the segments \( \overline{NO} \) and \( \overline{PQ} \) are equal, indicating that \( \overline{NO} \) is a copy of \( \overline{PQ} \).