How should one handle inter-minority appropriation? It's easy as a white person to call out a white person in a native headdress or a kimono, but should I even try if they are also a minority? I have an Asian friend who is going as a Mexican sugarskull for Halloween and I find it problematic 'cause it's based on a religious belief/tradition and a festival that is not Halloween. But I don't want to go all white savior on her, especially 'cause I'm sure we'll run into some douches in kimono.
I think you can point to resources where there are latin@s who talk about this, and maybe let her know that dia de los muertos is a sacred holiday where people in many countries celebrate and honor their dead, and sugarskulls are an important part of that so it’s offensive when you wear it as a simple decoration
maybe also send a message to http://thisisnotlatino.tumblr.com/ and check out this