I have heard this figure (4%) for many years. I did not watch the video, but what she probably meant was "original" forests. That is, those forests that developed after the withdrawl of the glaciers about 10,000 years ago up to European colonization. Almost all of our forests in the U.S. and parts of Canada have been cut at least once, and some two or three times. Certainly, the Eastern U.S. is more forested now than any time since the 1700s. In Ohio, we have less than 1% of the original or pre-settlement forests left. However, much of the Appalachian Plateau region of Ohio is covered with 2nd and 3rd growth forests.