I was 42 and living in Las Vegas. My mother wasn’t involved. I’m 65 now. Times may have changed but I haven’t. 
If one of my kids wanted to write to the Queen I wouldn’t stop them. I’d probably explain that she’s busy and might not be able to reply, but I’m sure the she gets letters from kiddies and 42 year olds all the time.
And the lady-in-waiting who hand-wrote Turble’s reply probably has answering fan mail as one of her official duties. As well as probably several other ladies: I expect that she probably gets a lot.
I’m sure her mail ranges from fan mail to letters from crackpots demanding that she fix the potholes outside his house, or fire David Cameron or whatever.
For my grandparents 50th anniversary (30 years ago, they’re both deceased now) my dad wrote a letter to the Queen asking if she would send her congratulations. He read the response at the party, which was from one of her assistants basically saying that due to the volume of mail the Queen receives she is unable to respond to all such requests and she only sends congrats for a 75th anniversary.
The governor of Florida (where my grandparents lived most of their lives, as required by law since they were Jewish :D) was evidently not quite as busy as the QoE and sent a very nice letter and his warmest regards.
Hmm, good question. This used to happen of course, but I dunno about modern times.
If one is actually a Knight of the Garter, there are quite a bit of ceremonial responsibilities, but that’s pretty rare.
There are a couple of honours which are awarded at the initiative of the monarch, for service to the monarch or the royal family. The Royal Victorian Order springs to mind; there might be others. However only the more senior members of the order get to be “Sir” or “Dame”; the rest get letters after their name, but no special form of address.
In circumstances where you would call plain Mr Ian McKellen “Ian”, you call Sir Ian McKellen “Ian”. In circumstances where you would call plain Mr Ian McKellen “Mr McKellen”, you call Sir Ian McKellen “Sir Ian”. If you called him “Sir Ian” and he didn’t want you to, he’d probably ask you to call him “Ian”, not “Mr McKellen”. (If he actually wanted to be known as “Mr McKellen” he woudl presumably have declined the knighthood.)
If you called him “Mr McKellen” he’d probably think that didn’t know, or had forgotten, that he had a knighthood. Whether he would regard this as a major faux pas would depend on whether he thinks you should have heard about, noted and remembered his knighthood.
My parents recently celebrated their 50th anniversary and we had a nice party for them. I now regret that we did not ask the Governor of New Mexico to send her congratulations.
The Order of the Garter is one that’s exclusively the Monarch’s prerogative as well. It’s mostly filled up with people you’d expect to be close to the Queen, the old blood landed aristocracy. It can only have 24 ‘regular’ members, the monarch and the heir are also additional persons who are automatically members, and the monarch can make members of the Royal family “supernumerary” members without counting against the 24 and I believe similarly she can make foreign dignitaries supernumerary members as well.
The monarch is still the “fount of honor” in the United Kingdom, while she only does it by custom for members of the Royal family she can still essentially create peerages at will, and has done so. Her grandson William was make Duke of Cambridge upon his marriage, and also created an Earldom and Barony for him as well. While I think the monarch would violate the rules about not doing anything controversial or meaningful if they just started handing out peerages to random politicians or people she just happened to like, I imagine in rare circumstances the monarch could probably still create a title for close friends of high standing in society. Especially since a peerage has no automatic importance after the House of Lords was reformed to only include a select number of hereditary peers. Most hereditary peers can no longer sit in the House and it is primarily filled by “life peers.”
My grandfather (a WWI veteran–I mention this because the letter mentioned his WWI service so whoever generated them must have been cross referencing with service records) received a letter from President Carter for his 90th birthday. I imagine they do not do that at 90 anymore, it’s too common an age at this point.
They do congratulatory messages for 60th anniversaries and up, also 100th birthdays. http://www.royal.gov.uk/hmthequeen/queenandanniversarymessages/anniversarymessages.aspx
Order of Merit is in the Queen’s gift too, and in a lot of ways it’s the best one - it tends to be academics and artists. It’s restricted in number too, and I think you get a nice dinner once a year on the Queen’s tab. I imagine the small-talk is fairly formidable: Order of Merit - Wikipedia
When Tony Robinson (Baldric from Black Adder) was knighted, he was quoted as saying “I’ll use my new title with abandon to highlight the causes I believe in, particularly the importance of culture, the arts and heritage and the plight of the infirm elderly and their carers,” adding, “I also pledge that from this day on I’ll slaughter all unruly dragons, and rescue any damsels in distress who request my help.”
So, that’s something to start with.
That’s not actually true. Of the 21 current Knights of the Garter, only 5 (Lord Carrington, Lord Ashburton, The Duke of Wellington, the Duke of Abercorn, and the Duke of Westminster) are hereditary peers, and the only one of those that’s a really old landed title is the Duchy of Abercorn, which dates back to the old Scottish nobility…they’re Hamiltons, descended from James IV.
Of the rest, the first Baron of Carrington was an MP from Nottingham who was the founder of Smith’s Bank, the Barony of Ashburton belongs to the famous Baring family of bankers, the Dukes of Westminster are descended from a politician who first got elevated to the peerage as a payoff for first backing the Newcastle Government and then got an earldom in exchange for voting against a bill to regulate the East India company. Then, obviously, there are the Dukes of Wellington, and I’m sure I don’t have to explain that title’s history.
Otherwise, in terms of non-hereditary peers, you have somebody who’s married to the Queen’s cousin, Gladstone’s great grandson, Winston Churchill’s daughter, and a whole lot of retired military officers, businessmen, and politicians…but very few of them are what you’d call “old families”.