well, there's always a room for improvement for a mindset like that. hoping she grows out of it though. 16 is the best age to be bitchy and tacky after all.
Lorde is a very different artist from Katy. She is an indie artist and her music is very distinguishable from Katy's.
Teenagers tend to be choosy and if she isn't comfortable with Katy, I understand why she would refuse.
She'd rather have some talented or other acts that deserve to be in her show.