Familiar and somewhat affectionate term for a young girl or young lady, often used by older people or in a friendly, informal context. The ちゃん suffix softens the word 嬢 (じょう), which on its own can mean 'young woman' or 'miss'.
近所の嬢ちゃんがいつも元気に挨拶してくれる。
The young girl in the neighborhood always greets me cheerfully.
おじいさんは店に来た嬢ちゃんに飴をあげた。
The old man gave a candy to the young lady who came to the shop.
The shop clerk called me 'young lady'.
少女 is a more literary or formal term for 'young girl', while 嬢ちゃん is a casual, affectionate way of referring to or addressing one.
お嬢さん is the polite, respectful way to refer to someone's daughter or a young lady, while 嬢ちゃん is a more casual, affectionate version often used with children.
The everyday counter for people: 一人 (ひとり), 二人 (ふたり), 三人 (さんにん).
A somewhat formal counter used for counting people, including 嬢ちゃん (young girls).
Derived from 嬢 (じょう, 'young woman') with the diminutive suffix ちゃん, which expresses familiarity or affection. The exact historical origin of 嬢 is uncertain, but it has been used in Japanese to refer to unmarried women or daughters.