Yes it applies to a child with no faith
The RC bit is because most children in the ET will have RC parents and may be brought up loosely in the RC faith so that a specific discrimination.
The Dont Preach website link is about children who follow no faith.
Article 42 give parents rights to be the decision maker on moral and social values. Section 3.2 on education would oblige the school to show how the State (not the school) has adopted the schools version of GI as being factual but the State will not have done this as the RCC still control the majority of schools and under RC faith law the RC school ethos can not teach that "God put a girl brain in a boy body"
Article 42A gives the child rights to his own belief
Article 44 to attend the school without the schools belief in GI
https://www.irishstatutebook.ie/eli/cons/en/html#article42
EDUCATION
ARTICLE 42
1 The State acknowledges that the primary and natural educator of the child is the Family and guarantees to respect the inalienable right and duty of parents to provide, according to their means, for the religious and moral, intellectual, physical and social education of their children.
2 Parents shall be free to provide this education in their homes or in private schools or in schools recognised or established by the State.
3 1° The State shall not oblige parents in violation of their conscience and lawful preference to send their children to schools established by the State, or to any particular type of school designated by the State.
3 2° The State shall, however, as guardian of the common good, require in view of actual conditions that the children receive a certain minimum education, moral, intellectual and social.
4 The State shall provide for free primary education and shall endeavour to supplement and give reasonable aid to private and corporate educational initiative, and, when the public good requires it, provide other educational facilities or institutions with due regard, however, for the rights of parents, especially in the matter of religious and moral formation.
CHILDREN
ARTICLE 42A
1 The State recognises and affirms the natural and imprescriptible rights of all children and shall, as far as practicable, by its laws protect and vindicate those rights.
See the use of the word belief (highlighted by ● )
RELIGION
H5>ARTICLE 44
1 The State acknowledges that the homage of public worship is due to Almighty God. It shall hold His Name in reverence, and shall respect and honour religion.
2 1° Freedom of conscience and the free profession and practice of religion are, subject to public order and morality, guaranteed to every citizen.
2° The State guarantees not to endow any religion.
3° The State shall not impose any disabilities or make any discrimination on the ground of
● religious profession,
● belief or
● status.
4° Legislation providing State aid for schools shall not discriminate between schools under the management of different religious denominations, nor be such as to affect prejudicially the right of any child to attend a school receiving public money without attending religious instruction at that school.
5° Every religious denomination shall have the right to manage its own affairs, own, acquire and administer property, movable and immovable, and maintain institutions for religious or charitable purposes.
6° The property of any religious denomination or any educational institution shall not be diverted save for necessary works of public utility and on payment of compensation.