” how is that an act of Congress?”
Federal Money = Establishment. And, through Incorporation, State Money = Establishment.
I would not want my kid to be taught ANY religion in school. Certainly not in a state with compulsory attendance.
And I think the argument that not teaching religion is a religion itself is ludicrous on its face.
That said, most public schools DO teach a form of religion. From Global Warming/Climate to Homo Normalcy and those should be considered when assessing Establishment.
The most the religious can hope for in our system of government is tax deduction for the cost of religious schools, and/or the freedom to home school. And the elimination of state pseudo religion.
Then you should be perfectly happy with the current policy. LGTQ has the floor and you are powerless to object. Your child can be counseled and treated for gender Diaspora with out your knowledge or approval.