It's only too fancy if you don't like it. You get to decide what is good for you to wear and what isn't, and it isn't some arbitrary rule about how 'fancy' someone's allowed to look.

[Elle give Peregrine's shoulder a squeeze.]

You are a beautiful girl, and you've got two beautiful girlfriends up there and a whole bunch of family who want you to have a good time and feel good about yourself. If you try it on and hate it, I promise we will look for something else.