giselle knows english and she interacts with western fans since she's a kpop/ 1d fan before so she should've known better about the n-word.
she did sing tia tamera by doja and that had the n-word in it but she didn’t use the verse that had the n-word. i think she is familiar with the word but sang it unconsciously/accidentally. it’s good she apologized and hope she won’t do it again in the future.

when they get called out for it.