Her right to find something offensive & you can't tell a group of people to feel a certain way, but that also applies vice versa. I can't wear a costume because you find it offensive? Same logic in religious views against gay marriage. It's like saying I can't have a donut because you're on a diet
also it's generally not offensive if a minority "appropriates" another culture. Like if a black person was wearing a kimono for Halloween no one would say anything, but would if it was a white person
cultural appropriation is a retarded concept. being fascinated by different cultures isn't something to be ashamed of. it's only an issue if you're intentionally mocking it