image from: http://www.kampie.info/reisverslagen/verslag_peru/maria_reiche.htm
Ms. Reiche theory is that the lines had something to do with an astrological calendar. This calendar, Ms. Reiche said, helped the Nazca Indians marked important events during the year, such as the arrival of Spring and also pointed to important stars. Some other scientists have said that this is incorrect. The reason is because it is difficult to determine exactly when the lines were created. Since the earth is changing is shape the stars have changed position in the sky. A computer program determined that only about 20% of the lines actually point towards the position of astrological symbols and stars that existed around the time of the lines.
Perhaps the most important thing that Ms. Reiche did was to make the world aware of the Nazca Lines. Had she not done so, they may have been destroyed. As it is a highway cuts the one of the drawings in half. But now, the country of Peru realizes that the Nazca Lines are a national treasure and they have worked to make sure that they are not harmed.
Here is an interesting fact. Remember the drawing of the figure that had five fingers on one hand and four fingers on the other hand? Maria Reiche, also had only 4 fingers on one hand. Because of an accident she had to have one of her fingers amputated. Maybe something like that happened to one of the Nazca Indians so that is why they drew the figure that way?