倩 owes much of its fame to the Shijing 《诗经·卫风·硕人》 line 巧笑倩兮 ('how charming her clever smile') describing the noblewoman Zhuang Jiang. From there 倩 became a standard literary word for an alluring smile and a popular character in women's given names.
culture
Famous bearer: 聂小倩 (Niè Xiǎoqiàn), the ghost heroine of the Tang-dynasty story collection 《聊斋志异》, adapted in the cult Hong Kong film 《倩女幽魂》 (A Chinese Ghost Story, 1987).
亻 is the left-side form of 人 (person). It marks 倩 as a quality of a person — pretty, charming, with a winsome smile — which is also why 倩 became a popular character in women's given names.
青 qīng provides the sound, shifted to qiàn. The same phonetic feeds 清 (qīng, clear), 情 (qíng, feeling), 请 (qǐng, please), 晴 (qíng, sunny) — the cleanest sound family in the language. The youth-and-vitality flavour of 青 also suits 倩's bright, fresh charm.