Your nanny has the right to be compensated for time spent travelling to and from your destination. Your holiday travel time is different from your commute and must be compensated.
Even if your nanny is sitting in a completely different row on the plane and they are not at all responsible for the kids, your nanny must be paid for the travel time because they are on the clock…
You might need your nanny’s help during these hours, so it’s only fair to compensate for their time!