I might get castigated in here for saying this, but I'm going to say it anyway.
I'm deeply uncomfortable with Christian brothers and sisters trying to impose the Christian lifestyle and Biblical values on non-believers. It just doesn’t work.
If you tell a non-believer that their whole lifestyle is contrary to Biblical teaching, is that going to trouble them? The more likely outcome is that the recipient's stereotype of Christians being biased, pious and small minded is reinforced. IMO huge sections of the church have been deceived by Satan into abandoning the great commission and instead replace it with laws of morality.
And Jesus came and spoke to them, saying, “All authority has been given to Me in heaven and on earth. Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age.” Amen. Matthew 28:18-20.
Read Luke 10:25-37. To me a transgender is a poor soul, robbed and beaten half to death by the pressures of this world. The church are like the Priest and Levite, crossing over to pass by on the other side, leaving him or her to die in their sin. Instead of spending time with them, trying to heal and introduce them to other agencies that can help that process, they just walk by on the other side or even worse, as in the case of this teacher, give them a good kicking as they pass. Afterwards, how would the victim in Jesus's parable feel towards established religion, or even God Himself whom the Priest and the Levite claimed to represent?
If a teen is struggling with deciding which is his true gender, then is outing him to his parents like pouring oil and wine on his wounds and bandaging them? How is that going to help in winning the battle for his soul? Is it not more likely to put him off Christianity for life, or even eternity?
IMO this teacher was quite wrong and showed levels of compassion comparable to the Priest and Levite and so deserved her outcome. She is quite wrong to claim she is a victim of discrimination, the school had a policy which she contravened and suffered the consequence.
LGBTQ are not our enemies, rather they are lost souls in the dark, needing the light of the Gospel. And even if they are our enemies, are we not told to love our enemies as our neighbour? “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ But I say to you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who spitefully use you and persecute you, that you may be sons of your Father in heaven; for He makes His sun rise on the evil and on the good, and sends rain on the just and on the unjust. Matthew 5:43-45 NKJV