Welcome Letter For A Salon How Do I Say The Following In A Welcome Letter To Parents?

How do I say the following in a welcome letter to parents? - welcome letter for a salon

I teach students and do not want a "child" of the sentence: "If an unusual circumstance prevents your child to use with their homework (sickness) may breach or other serious problem, a note to send your child in the morning, so he can will not apologize for homework. "

I do not mean "child", because, well ... It sounds as if the student in the 2nd Class, I must say ... Your child? or what?