I need to dress up as the daughter of a fashion designer, any ideas?

I think the daughter of a fashion designer would most likely be dressed in completely minimalist fashion. Wear a black or white dress with clean lines and shoes of the same colour. Carry a huge bag and slick your hair back into a high pony. Something like this: Model in a black dress

I'm guessing this is for a costume party or something? Good luck!

Then for that you gotta wear the latest fashion clothes awesome accessory and also have a change in the way you act; act like some fashion designer and wear clothes which show how talented you are but that's just to let people know you're a fashion designer's daughter, but honestly I would tell you to wear what you like, be you not someone else so just wear what you like that's the second best option!