She is Arthur's  (England's) younger and beloved little sister Elizabeth Kirkland. 

Quick bio  about Elizabeth Kirkland

Represents: London 

Age: 15

Hair color: Strawberry Blond

Hair length/style: About waist length, straight, and sometimes in pigtails 

Eye color: Greenish Blue

Height : 4'11'

Blood Type : A

Zodiac Sign : Capricorn

Most of the time she is real nice and proper, but if she is provoked she is a nightmare!

She loves her brother Arthur very much!

Her and Alfred don't really get a long well. Well mostly she dosen't like him. (She can't get over him becoming independent and hurting England's feelings.)