Dale Tryon did not meet Prince Charles in 1964, nor did he give her the name “Kanga”. She was named Kanga by Antony Tryon, whom she met and married, entirely of her own volition.
Antony Tryon was always a good, successful husband and a generous provider. As for Lady Tryon's mental health, many believe that she suffered from undiagnosed bipolar disorder that was triggered by her ghastly cancer episode and exacerbated by her desparing suicide attempt.
Some suspect that she was prescribed Prozac when she entered Farm Place and, overwhelmed by suicidal thoughts as a result, jumped from the window. Her subsequent claim that she was pushed was her attempt, many believe, to make some sense of something that was entirely uncharacteristic and inexplicable to her. As her behaviour became more erratic she was admitted to a mental hospital but was soon out. Lady Tryon spent her last months in Australia and touring India, where she unfortunately contracted an infection that ultimately led to her death at age 49.
I doubt that anyone who knew the luminous Lady Tryon remained unmoved by her situation, and that includes Prince Charles, it's said, and whom, I believe, has far more humanity than many people give him credit for. About the only thing that gossips and scandalmongers get right is that Dale Tryon had a tremendous and infectious joie de vivre and that she is sorely regretted.