I don't think she said 100 years....something about 200 years till the sun enters its death cycle.
Others have spoken about the crystal core of earth changing and the surface changing as well. If you look deeper you will see this has happened on earth before. Many of the "underground civilizations" were actually ancient surface dwellers who listened to the earth, and survived the "changes" it procured on itself.
Yes, I also don't agree with her future view on the timeline. Her info became distorted at some point. Much of it is still true, like the Source- its function and how the dimensional "physics" work, as well as some healing stuff. But the future timeline stuff is just wrong IMO.