I sent a email to the Maryland ACLU asking their position on the case,here is the response that I received.
"Here is a response to your inquiry regarding a student reading the Bible
during lunch:
We don't have any formal position, because we weren't asked to take the
case, but that in general, we don't believe school officials are under any
obligation to tell a student that he or she can't read a bible to themselves
during free time in school, and that prohibiting a student from reading that
book, and not others, on school grounds would be improper.
Thank you for contacting us.
Sincerely,
ACLU Legal Intake Staff"