Never used independently in modern Chinese. Its value is as a phonetic root: it sits inside 婴 (infant — the traditional 嬰 is a neck-strung-shell phonetic over 女) and from there into 樱, 鹦 and 缨.
memory
Two shells 贝 side by side are shells threaded together as a necklace. That image is why every 婴-family character carries the yīng sound.
Components
semantic
貝bèi
cowrie shell
The first 贝 (cowrie shell, an old form of money and ornament). Paired with its twin it pictures shells strung together as a neck ornament.
semantic
貝bèi
cowrie shell
The second 贝, beside the first. The deliberate doubling is the whole graph — a row of shells on a string, the necklace meaning of 賏.