1 hour a day, every day, of each of the subjects you listed should be plenty. Anyways, anything longer than that is difficult for adults to pay attention to, le

1 hour a day, every day, of each of the subjects you listed should be plenty. Anyways, anything longer than that is difficult for adults to pay attention to, let alone children. If you had an hour per day of instruction/guided practice at the piano, you would absolutely get better. You probably wouldn't become a virtuoso, but the school system isn't designed to make people into virtuosos. That requires more practice.