I was never aware of why it was called jimmies growing up. Reading up about it. I saw this.
"According to the brand Mr. Sprinkles, the name “jimmies” wasn't inspired by Just Born at all, but was in fact a name given to the sugary confections after Dr. Sidney Farber, an uncle of Edward Brigham, created a charitable organization named after one of his patients called The Jimmy Fund, which still exists today."