Statistically speaking, JoJo Siwa does have a following that's made up mainly of little girls. However, these days, nothing is ever exclusive for girls or for boys anymore. Society has been working hard to break away from gender stereotypes. So if there are boys who love JoJo Siwa and they ask for a JoJo Siwa cake for their birthday, then get them one. Use your creativity to make it look less girly if that's what concerns you.