18 y/o girl Christmas present ideas?

She already has
-iPhone
-wants a Mac but it is out of budget
-uses phone as ipod
-needs clothes for uni next year but has to pick them herself
-has a car already

She is interested in fashion.
Any ideas other than gift vouchers and jewellery.

Budget $100-$200

Just give her $200 and call it a day. That the best thing to give if you don't know what to get.

You could try giving her something like this:
https://www.etsy.com/shop/BookishlyUK?ref=pr_faveshops
https://www.etsy.com/shop/Delightedly?ref=pr_faveshops
https://www.etsy.com/shop/IdeaCase?ref=l2-shopheader-name
https://www.etsy.com/shop/TheCuriousCaseLLC?ref=l2-shopheader-name
https://www.etsy.com/listing/118769791/personalized-iphone-case-photo-iphone-4?ref=sr_gallery_15&ga_search_query=i+phone+case&ga_view_type=gallery&ga_ship_to=ZZ&ga_search_type=all&ga_facet=i+phone+case
https://www.etsy.com/shop/LeozHeart?ref=l2-shopheader-name
https://www.etsy.com/shop/CocoLake?ref=l2-shopheader-name
https://www.etsy.com/shop/GoldenDaysDesigns?ref=l2-shopheader-name
https://www.etsy.com/shop/stephaniekiker?ref=l2-shopheader-name
Hope i helped!

This shop has really cute jewelry and wall art. Very inexpensive and within your budget.

vintagelacedesign.etsy.com