A care plan or any notice required to be given to a person under section 9, 10 or 15 must also be given—
(a) in the case of a person under 18 years of age who has a parent or guardian, to the parent or guardian; and
(b) in the case of a person who has attained 18 years of age and in respect of whom a guardian has been appointed under the Guardianship and Administration Act 1986 , to the guardian.