The most common and most likely answer to this crossword clue is the 6 letter word EUNICE
I've seen this crossword clue in The Daily Telegraph
E
U
N
I
C
E
More clues leading to the result EUNICE
- Woman’s pro-European statement?
- Girl a good advertisement for Brussels?
- She‘s seen in a classy French resort at end of June
- She can turn out to be an upper-class niece
- Woman from French city assigned to organisation based in Brussels
- Girl from French city undermining continental community
- Girl is English, superior, and pleasant
- Woman, English, upper-class, and refined
- European Union’s fine for this woman
- Pleasant accompanying English university girl
Buddy explains!

The straight part
We know that "girl" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case girl = eunice.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.