This child's handwriting is very clean and refined.
Tips
usage
清 = 'clear / clean', 秀 = 'elegant / graceful'. Describes an understated, delicate beauty — usually a face (清秀的脸) or handwriting/artwork (字迹清秀). Contrast with 漂亮 (pretty, general) or 艳丽 (gaudy, showy).
register
Tends to be used about women, children, and young men with refined features. Per 《新华词典》: 清爽秀丽,不俗气 — 'clean, elegant, not vulgar'. Considered a classy, literary compliment.