There is a lot more out there about this incident and like all things there is something deeper going on.
This teacher has not (for whatever reasons) built the relationships needed to be a successful teacher with at least one group of her students and an antagonistic relationship has developed with that group. It may, of course, be wider spread. To complicate matters, she has posted her feelings in a manner in which they were visible to the world which is always unwise. It will not surprise me if she is not put on an improvement plan for the remainder of the year.
It appears that the teacher had FB set so that her wall could be seen by the public. That alone was not smart, but the words should never have been written in the first place. If her FB is anything like mine, it is full of casual friends. I just don't know them well enough to share the inner workings of my job and relationships. Discretion is the better part of valor.