Completely emotional spent, and on other people's kids!

So, a letter went home on January telling the students and parents about a meeting next week Tuesday. Then a notice was in the weekly email newsletter sent to all parents, finally we sent an email yesterday reminding them all of the meeting. One parent apparently didn't see any off these and is upset over the supposed five days notice we gave her. She apparently asked the music booster parent on charge about a month ago to get it of the trip. You tell me if I'm inferring a tone. Here's just a clip "As my husband and I shall be in Arizona on business on the 20th and absolutely cannot make a "mandatory" meeting, may I cancel Xxxxx's trip? (I'll get her there for the competition - but neither she nor I want her to take the rest of the trip. Wicked! is so low brow, watching it once was painful; I wouldn't ask a prisoner to suffer it twice.) I did ask before but was told it was too late to pull out ~~ I presume you now have that option as this meeting is mandatory.