Well, the truth is, they don't get 6 years to decide. They need to know this by 14u, if playing on a A-level Travel team. The sole purpose is to make the team showcase ready so, if the girl isn't ready to make the commitment to playing at that level to attract college coaches, oh well. There are no other options for that age group, other than high school.
What I mean is that you really can decide if you want to play college up until the minute college starts. Yes, you need to get an offer, and to get an offer you need to be on the right teams playing the right competition. So yes, you have 6 years to decide if you really want to commit to playing college ball. But if you bail out at 12 (or 14, in your example) you then don't have that option to play in college probably.