I am not sure I would have felt comfortable with letting my daughter live on campus at age 15 either. But glad to hear that you have at least looked into the living on campus situation.
I don’t know that they took my daughter’s age into account when she applied - she was a traditional high school senior (skipped 4th grade) so unless they looked at her birthdate, they would not have realized she was 12 - 18 months younger than her grade peers.