My friend came out as genderfluidWatch
It might be confusing or nonsensical to you, but this is evidently quite important to your friend so you have to get used to it. A great start would be to ask what pronouns they now want to use
Maybe they are embracing what your Gods created them as, maybe it is in fact you who is wrong.
It's not going to affect you in anyway whether you agree or disagree. It could even be something she's been struggling to deal with don't make life anymore difficult for her.