To determine if the segment \( \overline{NO} \) is a copy of segment \( \overline{PQ} \), Brianna needs to show that the lengths of the segments are equal. Therefore, the correct response is:
She needs to 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 ensures that the length of \( \overline{NO} \) is the same as the length of \( \overline{PQ} \).