How can i tell my sister shes not vietnamese?

like the other person said, it is probably a phase. however, i can relate to you.....i have a cousin she is african-american, 20 years old....but she loves CHINESE boys...she loves their culture, music, BOYs, she is learning the language, and is even going to visit china in october, she has chinese friends too. there is NOTHING wrong with embracing another culture, but you still have to know who you are. My cousin tries to make herself look chinese, she is a light-skinned girl and has asian shaped almond eyes, so that really went to her head....she had dyed her hair jet black....she straightens it as straight as it can get.....she tries to act chinese, she really wishes she was chinese.and it gets aggravating sometimes. i understand where you are coming from, but there is really nothin we can do