Leaving aside the fact that, legally, not allowed to work up to 18 years, I do not think the babysitting is sick. And if babysitting can be considered a work. Take care of a child or more children is a pleasure. You can do many enjoyable activities with their children. They are nice and with a rich imagination. I do not know if being a babysitter is one whose earnings have necessarily declared. I know that any income should be declared and taxed, but, for example, my sister is employed as a babysitter for my two children. I paid 5$ per hour and I am not interested if she declared the income to be taxed.