Doubt very much Caroline would be at a Trump rally or play along with her brother at all.
After reading RFK Jr.'s diaries, no surprise if John would have wanted to get as far away from her as possible.
>https://www.vanityfair.com/news/2013/11/rfk-diaries-intense-family-drama-jfk-jr-death
Robert writes that, three days after the crash, Kennedy family members told Carolyn’s mother, Anne Freeman, that, while John Jr. would be buried in the family plot in Brookline, Mass., they “could do with Carolyn as they pleased.” Ultimately, this ended as a moot point, as both John and Carolyn were cremated and buried at sea.
But the diaries indicate that there were some very unpleasant interactions behind-the-scenes, particularly between Ed Schlossberg, Caroline Kennedy’s husband, and Anne, as he “bulled, bullied, bullied the shattered grieving mother,” according to the diaries. “She says she wants to start an ‘I hate Ed’ club.”
The diaries also reveal that Carolyn once confided to Mary that John Jr. and his sister Caroline had been quarreling about furniture in their Martha’s Vineyard estate which had belonged to their mother. Carolyn said John was “so depressed” about their fighting, and John told Robert “how hurt he was by Caroline’s actions.”