What does the cryptic crossword clue "Quaint northern child growing up fast? (5)" mean?

The wordplay uses a charade (building blocks). TWEE (synonym="=quaint, sentimentally pretty") + N (synonym="=northern") = TWEEN The answer is TWEEN.

Quaint northern child growing up fast? (5)

Independent Cryptic #11629 | 27 Across | 2024-01-18 flower