EN,
It would not be an issue of unjust discrimination.
vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_19920724_homosexual-persons_en.html
Consider the quote commonly attributed to St. Francis “Preach the Gospel at all times, if necessary, use words”. This is far more of a paraphrase if anything, as it refers to a time where he just went through a town performing good acts, and referred to it later as preaching the Gospel. But the point is true.
This teacher DID, in fact, teach against the Church, by her actions. Actions are what we, and the Church can judge, not people. At it was her actions that brought about her dismissal.
So no, the Church does not treat your community (or anyone else), with anything but love and compassion. However, it does reject sinful acts, and yet offers Mercy for all those who repent of wrongful acts.
All this teacher had to do was repent and make every effort to leave the sinful aspects of her life behind. That would truly be a preaching of the Gospel, but she chose not to, and thus the Church had a right and Duty to protect her children from false teaching.