Charles attended the birthday party of Austin McBroom and Catherine Paiz's daughter Elle, who are known as the ACE Family on YouTube.
In video posted online, Charles sits next to Jenner, who's got Stormi on her knees.
Charles recently canceled his upcoming Sisters tour amid the drama.
“Obviously the past few weeks have been a roller coaster and I’ve been dealing with this,” he said as he made the announcement on his Instagram Story.
“I am trying to move on with my life and focus on good things that make me happy and they can take my mind off of things,” he added. “I feel that I can’t deliver that best version of James right now, and that sucks but I’m working on it, I promise.”
At the height of the feud, Charles had lost 3 million YouTube subscribers in the span of a weekend.