I went looking for the usual DM sycophancy on this sort of thing and didn't find it, surprised it's out on Twitter if embargoed
It has made me think "oh Diana" a little bit, which normally I never do.
RE their educations
It was extremely common for the education of girls in that class and at that time to be considered "a waste of money" for what would they be bar wives and mothers? Considering the war was on its way, and Britain would change forever and HMQ herself would train as a mechanic its mindblowing to consider how unthinkable that prospect would have been just 10 years before. The Crown shows that the Queen once heir did take some private classes at Eton but they would have been basic and largely history based
The Mitfords who I've mentioned before (and I promise I won't bore on 
but they were the same social sphere as The Queen and Margaret) suffered a similar fate. For the majority of them, it was no big deal for their social circle was full of their like. Nancy and Jessica however, moved in diverse company and both are said to have felt burning anger at their ignorance and inability to keep up. They refer to it in letters when they are middle aged so it rankled with them that much.
It's amazing how Britain has changed in 100 years and nowhere is that change more marked than in the Royal Family whose latest joiner a divorced American was previously the very reason that HMQs Uncle had to give up the throne!