Oh I liked her feist! However (and in the expectation that she'll find a way to keep track of this) I've a couple of points.
First, high fever isn't the first symptom of tonsillitis. She would've known she was feeling poorly (and potentially infectious) a couple of days beforehand, and that was the time to contact and cancel. I had a punt (not her) cancelled in December for the same reason. A couple of days advance notice, professional, amicable, and we re-arranged. Simple, and reputation enhancing rather than damaging.
Second, she wanted us to validate her perspective but that should be mutual. Radio silence on the day of a punt isn't communication! She needs to respect that punters may need to create opportunity and availability to punt, and that by her behaviour she scuppered that for the OP. No respect whatsoever.
Third, she's allowed to speak up for herself but it's difficult not to translate her shite management of a dispute on here to how she might be if things weren't going well in a punt.