http://www.ncaa.org/student-athletes/future/eligibility-center/what-verbal-commitment
It just means the college coach "intends" to have her sign a National Letter of Intent when she can... senior year.
The only athletes I know that have had a college back out of a "verbal commitment" are when a coach gets fired and the new coach will not honor the verbal commitment.
Also, I know of a few athletes that had the college take away their verbal due to getting bad grades/issues with behavior.
Also, they will remove the offer if she does not live up to the "expectations" of GPA and SAT score.