I'm no huge fan of Charles but he stopped seeing Camilla when he and Diana got together, something many confirmed to be true. Their affair wasn't restarted until 1986...after she had stepped out with the police officer Barry Mannakee and he had to be transferred yet to many, Charles was and is seen as the one in the wrong who stepped out first. Moreover, Mannakee wasn't the only one whom she cheated with/got close to while married. There was also Hewitt, James Gilbey, and Oliver Hoare among others. That's why I think it's so funny she used the 'there were three of us in the marriage' regarding Camilla, more so when she was the other woman at least twice with Will Carling and Bryan Adams as his ex said he did admit to an affair with Diana which is why they split, which Paul Burrell confirmed seemingly to a few people. She also harassed the men and their wives during and after the affairs. One example was Oliver Hoare who got over 300 calls and when it was reported, the police found she was the culprit.
As you say, she did a lot for charity and she should get credit for that but her death caused many to wear rose-tinted glasses where she was concerned and it continues to this day.