I asked my younger cousin who is 23 what she wants for her birthday, and she said "cute clothes." I am thinking a dress or a coat with girly bows or ruffles. Do you know a designer or a store sells lots of cute girly clothes?
aquahot, top shop! I am your cousin's age and I love bows and ruffles so I know where she's coming from. I buy stuff from TopShop from time to time. Price is very agreeable and the styles are very cute. The size 2(their smallest size) is"okay" on me..could be a bit tighter, but if you cousin is small too, I'd recommend that brand!
Edit:
I picked out some things your younger cousin might like!
another vote for anthropologie!
i'm 20, and this store is absolutely perfect for the "cute" look! lots of cute ruffles, bows, and girly/classy clothing!