And that's the beauty of education, it follows a wide arc. Some kids can manage multiple activities, some cannot. Nothing exceptional about your kids in that aspect (LOL I mean all mamas think their kids are exceptional, myself included) they are simply different. some kids pick things up easy, some do not. some have an affinity for certain areas, some do not. Some will be national honor society members, others will not.
Most of the kids I know get average, every day teenage jobs such as fast food, retail, manual labor.
My son is not sure about what he wants to major in and that's perfectly A-ok, not every teen has to have all the answers at 17.
My brother played basketball and got grades good enough that enabled him to get into the naval academy, Me, I had to work hard for every B I earned high school through college.
It's not a about "worrying", it's about knowing your kid. why should I force my kid to get a job, in what is probably a minimum wage job when I know that's not conducive to his education? Even if it was in a field he thinks he would want to do later in life, it would be pretty counterproductive wouldn't it, if working caused his grades to drop, now wouldn't it.