In this chapter:
I. "Child" means a child or children at least 6 years of age and under 18 years of age who is a resident of New Hampshire.
II. "Nonpublic school" means a nonpublic school approved pursuant to rules adopted by the state board of education and administered by the department of education and which has agreed to administer the relevant provisions of this chapter.
III. "Parent" means a parent, guardian, or person having legal custody of a child.
IV. "Resident district" means the school district in which the child resides.