The ideas that Amelia Earhart advocated did in fact change history, but it is not really accurate to say that they affected history because of her. She was one of the influences that allowed the ideas that she believed in to move forward.
Earhart's ideas were mainly concerned with the importance of flying and with promoting women's rights. Both of these ideas have changed the world since Earhart's time.
For example, airplanes have had a huge influence for good and bad. On the bad side, they have been used as bombers to transform war and cause huge amounts of destruction (WWII). On the other hand, they have given us a great deal of mobility and have allowed people to travel much more than ever before.
If anything, the increase in rights for women has changed things much more than airplanes. The fact that women are now seen as essentially equal to men has changed the lives of practically every person in America. It has changed the way we conduct our family lives and our marriages. It has given more opportunities to generations of women and has generally made our society more just and equal.
Earhart did not cause these changes to happen, but she and others promoted these ideas which have changed the world.