Can you believe it? To a 12 yr old child!
Well, yes, after many of the things that we have read about on this forum and things many of us have personally seen.....
What if she was out in field service? Would she conclude that a twelve year old is unworthy of being witnessed to?
Why would she automatically presume at a school that your daughter should be judged as unworthy to be spoken to? What a self-righteous @$$.
On the upside, your daughter must be very competent and well thought of in school. She has a job in the office. She also must have a good measure of self-confidence because she did not let this person get her down.
That is a tribute to your skills as a parent.