Convert decimal to a fraction 0.18?

0.18 = 18/100
Simplfy 18/100 and you get 9/50

No, she is not using the protector correctly.

Because base arm (ray) of angle is not coinciding with line of 0° angle.  

Correct Method of using protector is following:

Step 1: Place the protector so that the mid point of its straight edge lies on the vertex of the angle.

Step 2: Cover the base arm (ray on base) of the angle by the zero angle line of the protractor.

Step 3: There are two scales on the protector. Read that scale which have 0° on the base arm of angle.

Step 4: Finally, read the scale where the other arm (ray) crosses it.