We all get hit by students and their parents like you did. I had one especially
manipulative little rhymes-with-witch freshman girl last year (ooooo-ooooo, feels so
GOOD to type that!). Her mother couldn't control her, yet blamed me in particular for
the problems the girl was having (I think since I'd taught her in elementary). The
girl was obviously playing both ends against the middle, telling me one thing and her
mother the opposite. I found that insisting on having her present when her mother
wanted to speak to me, in the vice-principal's office, would cause her to backpeddle and
retract parts of her story and often reduce her to tears. At that point there wasn't
anything sensible her mother could say, though she tried.
Since then, if I suspect an angry confrontation from a parent, I request the student be
present and we meet with the principal. If I'm taken by surprise in my room, I just
clam up and let the parent vent. You really can't argue or reason with someone that
Hang in there, girl.