Kids should always shower at least once everyday to keep them clean and healthy.
Kids usually get more dirty than adults do especially if the kids are out playing in the dirt or just playing outside in general.
If your kid doesn't take a shower everyday and change their clothes then the kid may start to smell and the teachers may notice in school and then have CPS investigate.
If the child won't shower on the weekends or when they are not going to school then it's not much of a issue but they should always be wearing new clothes everyday because the school and others could see it as neglect if they show up to school wearing the same clothes they wore the day before.