I have a vampire player and whenever she wears a thieves guild hood or the guild masters hood it doesn't show up and her hair is half there! Is it the hair style or a vampire thing? and is it fixable?

This is a bug that occurs when you are a vampire. It occurs with several hoods in the game, including Thieves Guild hoods and I think Dark Brotherhood/Assassin hoods as well. It has nothing to do with the hair style you choose. There is no fix other than being cured of vampirism.