She did use many words in the some 7000 pages of Harry Potter books and invented some words herself. Most of the spells are loosely Latin based and many of the names and places are based off of real people.
If you meant change the world, I would say she did. She was the first person to become a billionaire by writing books. She also is an incredible writer and a revolutionary children's book writer. Before the series, there really were no 'top of the line' children's books. She contributes to countless charities and is a most definitely a person who has greatly influenced society.