She is the brain-child behind the curriculum I'm using for homeschooling. She espoused the method, and some homeschooling moms put together the curriculum at amblesideonline.org. Here's a short article they wrote to explain her ideas:
Charlotte Mason was a British educator (1842-1923) who believed that education is more than passing exams, getting into the right college or job training. She said education is "an atmosphere, a discipline, and a life." It is about finding out who we are and how we fit in the universe God created.
Her ideas were ahead of her time - while others thought children were empty slates to be filled with information, she believed they were people capable of independent, intelligent thought and that they needed vital ideas, rather than dry facts, to feed their growing minds. She thought children should do the work of dealing with ideas and knowledge rather than the teacher acting as a middle man, dispensing filtered knowledge.
The Charlotte Mason method utilizes narration instead of comprehension exercises; copywork for handwriting; spelling and grammar modeling; nature observation for early science; and literature, poetry, art and music to give children's minds beautiful ideas to feed on.
Books are chosen for the literary quality with which they were written, and even more, their ability to develop the whole person and inspire one's character. The curriculum is geared towards building character with the use of personal habits, quality books, teacher guidance, the work of the Holy Spirit and personal reflection.