I think it would have been great if, when he said that stupid "whatever love is", she had taken the ring off on the spot and handed it back to him. On the telly
Oh yes Gonegirl 
Must admit, that "Whatever love is" remark made my blood run cold. She must have felt hurt.
It was almost like "She'll do for now to provide the heirs I need."
Diana at 19 was shy, insecure and uncertain, not at all manipulative or scheming. Once hurt by Charles, the wormed turned, and rightly so. Good for her! She played him at his own adulterous game because she was hurt and betrayed and sidelined - by Charles and his family and his coterie of posh, older friends.
I cheered her on for fighting back.Maybe because I had a rotten, neglectful, selfish husband at the time too, and small children. I felt her isolation and pain because mine was similar. She could have stayed quiet and meek within that gilded cage and not rocked the boat, adopted the regal stiff upper lip and the blind eye to his dalliances but she was hurting. Wouldn't any of us felt lonely, unloved and betrayed? By then she had found her feet so she played him at his own game. I liked her immensely. Divorce was the only way forward for both of them.
I think Charles is happy with Camilla. She is right for him, but the oaf should have declined marriage to Diana. He may have tried to love her, but they were very different people and he had a royal life he maintained without her. He continued his affair with a married woman. That was cruel.
I feel Harry and Meghan are very different people too, but Harry will make it work I imagine. One wonders when the newness of it all wears off ( screen star sexy wife, wedding, new glamorous 'friends' new baby, new home, new way of life) if they'll grow even closer. Harry does seem like a very different, spoilt, stuffy, opinionated, conceited and almost arrogant young man these days. His relaxed charm, sense of fun and friendliness seems to have deserted him.