My parents-in-law take care of the children at home, and we are in other provinces, but the teachers in the class often ask the children to hand in their homework?

No, it's better to communicate face to face. Otherwise, people will think that you are playing very carefully. This meaning is big or small, let's say it face to face. But more children communicate with their children themselves. If you can, bring more children by yourself. This is really important for children. Lack of companionship and correct education in all aspects of children's formation will really affect children's life.