Your child cannot be forced, it is illegal. If your religion or beliefs are being disregarded they can be sued, https://www.federalregister.gov/documents/2017/10/26/2017-23269/federal-law-protections-for-religious-liberty
Principles of Religious Liberty
"Religious liberty is a foundational principle of enduring importance in America, enshrined in our Constitution and other sources of federal law. As James Madison explained in his Memorial and Remonstrance Against Religious Assessments, the free exercise of religion “is in its nature an unalienable right” because the duty owed to one's Creator “is precedent, both in order of time and in degree of obligation, to the claims of Civil Society.” [1] Religious liberty is not merely a right to personal religious beliefs or even to worship in a sacred place. It also encompasses religious observance and practice. Except in the narrowest circumstances, no one should be forced to choose between living out his or her faith and complying with the law. Therefore, to the greatest extent practicable and permitted by law, religious observance and practice should be reasonably accommodated in all government activity, including employment, contracting, and programming. The following twenty principles should guide administrative agencies and executive departments in carrying out this task. These principles should be understood and interpreted in light of the legal analysis set forth in the appendix to this memorandum."
You cannot be forced, it should be reasonably accomadated in all government activity, which includes the schools.
