“So she held her head high and left…” Self pride is overrated. If the school asked her to remove it, just remove it and complain later. There were several kids at my high school that did stuff similar, and the school told them to take it off or they couldn’t participate. So, they took the garbs off, graduated…and afterwards, tried suing everyone… but for that moment, just do what you need to do and participate in your special moment.