Colloquial, affectionate term for a cute person, often used playfully or endearingly. Can be used for children, romantic partners, or pets.
See also: かわいこちゃん
うちの可愛い子ちゃんがまたいたずらした。
Our little cutie got into mischief again.
彼女はいつも「可愛い子ちゃん」と呼ばれている。
She is always called 'cutie'.
From 可愛い (kawaii, 'cute') + 子 (ko, 'child') + ちゃん (-chan, diminutive honorific). A straightforward compound used as a term of endearment.