I'm a Christian and wouldn't accept that at a public school.  You have Sunday school, youth groups, home, and church for those things.  School is school.  Not only is it inappropriate to treat the classroom like a pulpit, its illegal.  

They gave this girl a horrible start in life.  Reducing her grades and jeopardizing her college opportunities could have long term effects.  I hope she wins big and I hope the authorities come in and clean out that school.