Am enjoying all the valuable information and speculation. About writing notes: I have never in person seen a real palace, but in pictures, to me, they seem HUGE. Can you imagine a working, unhealthy mother of five trying to run around the palace, looking for her children, to tell them to wipe their noses or something? Seems to me that just distance alone would argue for note-writing, sent by servants, as the most efficient and quickest way to get word to one's child, unless one is with them at the moment.
I also feel that royals, by their very nature, are somewhat isolated from the "common man" and probably don't have a realistic idea of how non-royals raise their children. It's just the nature of the beast, I think, that being royal also means being a little different from the rest of us. Even today, Queen Elizabeth's children have had problems with their marriages...some due to their parents' lack of involvement with them during their upbringing.
Perhaps the "job" of being a royal is much, much different and more difficult than any--or most of--us can even imagine.
Also, perhaps some royals seem so very isolated because to them, they're the only ones who can trust each other.
While I think it would have been marvelous to have lived in a huge, beautiful home, and have had gorgeous dresses and jewels and the very best of everything, and been waited on all the time, I can also see how that kind of life can easily interfere with self-discovery and a limited world view.
Just thinking.