This is a common misconception. Recruits can't sign their National Letters of Intent (aka NLOI, NLI or LOI) until one of the two signing periods in her senior year of high school.
The early signing period for basketball - Nov. 13 - 20, 2013
Regular signing period for basketball - April 16 - May 21, 2014
(
here's more info on LOIs)
LOIs signed early are not valid.
Many recruits, although not all, give an oral (also called a verbal) commitment. These are not regulated by the NCAA and are not required. It's simply a statement by a recruit that she intends to sign her LOI for that school during one of the signing periods. It's not binding on either party and, in fact, it's not unknown for a recruit to change her mind and make an oral commitment elsewhere. UConn had a recruit give an oral commitment to the Huskies at the Super Show, then a week later declared she was going to, um, LSU? but when she signed her LOI it was to Florida which shocked everyone, including the LSU and Florida coaches. No rules were broken since there are no rules for oral commitments. (btw, she played 2 years at Florida before transferring to Baylor)
Incidentally, schools can pull scholarship offers at any time including after a recruits gives an oral commitment. There've been several times when a school has pulled an offer late, especially in football. Unethical maybe, but it breaks no rules.
You may know all this stuff, Sonny. I'm just tacking this onto my response to you for general informational purposes.