The public transit in Switzerland is excellent, but also nowhere near perfect.

I think we've all experience imperfect rail times.

on a side note---how do you personally define 'late' 5 mins? 10 mins? 30 sec? Could be a relative situation.

Also out of all fairly in random events, such 'late' events, although not occuring frequently, can occur 5-6 times in a row. Perhaps your daughter has just experienced some bad luck.