(a) An individual who was under the permanent managing conservatorship of the Department of Family and Protective Services on the day preceding the individual's 18th birthday is entitled to a preference in employment with a state agency over other applicants for the same position who do not have a greater qualification.
(b) This chapter does not apply to:
(1) the position of private secretary or deputy of an official or department; or
(2) an individual holding a strictly confidential relation to the employing officer.