Should I use the same subtitle?

I wrote a short story for middle grade called Fair Danger: A Jonno and Kyle Adventure. The two boys, Jonno and Kyle are the protagonists. They are also the protagonists for my upcoming novel. Since then I have written a short story about a minor character in the novel, a 30-something woman who is Kyle’s nemesis. This new story is told from her point of view. The working title is A Heart for Sheep. I am not sure if I should use the subtitle A Jonno and Kyle Adventure if the boys only make a minor appearance in this story. Would the subtitle make kids think the story will be about the boys? Would they be disappointed to find out it’s about Miss Loretta and her problems? I don’t want to set up false expectations with the subtitle, but I do want to link it to the other story.