My sim family has 3 children currently: 2 teenagers and 1 child. I signed up all 3 children to different boarding schools at different times, but the first teenager hasn't gone yet, while the rest has. It says under the career tab that she's enrolled in boarding school, but her car hasn't arrived. It's been a few Sim days and she's almost aging up to young adult.
I've also tried resetsim and it didn't work.
I don't know what's going to happen when she ages up and "graduates" from boarding school that she never went to