Diana was much too wild to be Queen.
This^
But, especially this:
Yes Diana was naive and sheltered in the ways of the world, poorly educated and living in the sloaney bubble. But she would have been very familiar with the marrying patterns of the aristocracy and I don't buy the fact that she thought he was madly in love with her. More that she really really wanted to be Princess of Wales and thought that the rest of it would follow in time - the idealistic teenage "i'll make him fall in love with me" thing.
Diana had the Royal and family connections and frankly, the time, to be floating around Balmoral Castle in the Summer/s of the early 1980's. Helping the Queen with the daily bbq preparations etc.
She flirted with Charles (whom she had a crush on when he was dating her sister) i.e. teach me to fly fish, Charles. (Although she was anti-blood sports, so that doesn't bear close scrutiny.)
One summer night, whilst sitting around the camp fire, Diana whispered in Charles' ear, 'I know you were close to your uncle Louie' meaning L. Mountbatten.
This, it would seem, is all Charles needed to feel it was as his deceased uncle had prophesised in a letter regarding his possible future bride. (That and Phillip hinting, phwoar, go on son, if I was twenty years younger I would.)
So, that Summer seemed to be the sum total of their courtship. I wondered, did they never go out ? Stay in ? Have a row ? Go for a walk ? All the normal coupley things, IMO.
Charles proposed marriage to Diana in the nursery at Windsor Castle. The implication being, 'marry me and produce babies, please.' There was no excitement on either side regarding proposal and acceptance. No real hint of romance, either. I accept there's no formula for proposals regardless.
He immediately phoned his mother afterwards and stated, 'it's done or I've done it' or words to that effect.
So, I'm not sure about Lady Fermoy and the Queen Mother pushing Diana forward as a likely candidate as Charles' bride. Albeit Lady Fermoy was one of the very few people who knew how unstable Diana was and, like the rest, said nothing as the pressure was on to get Charles wed and not only did Diana fit the bill, she was daft/naive enough to fall for it. On her own agenda as well i.e. she thought by marrying the Prince of Wales, the future king cannot get divorced. Which may have been a response to her parent's failed marriage. She fancied being a princess and living in a castle, too. Until after getting married, she realised it was all codswallop and she was stuck with boring old Charles.
What she needs is a riding instructor/tennis coach. Which is Royal speak for, why don't you have an affair ? We can arrange one for you.
On getting engaged, Charles careless remark, 'whatever love means' didn't bother me as much as describing Diana as, 'rather lovely.'
Looking back on footage of that interview, it's obvious how pointed that question put to Charles by Dimbleby was.