Some children's earrings are not only suitable for babies and children, but also adults. For example, we expect our lobes will be too thick to wear children's earrings, but in most cases, our ear lobes are only marginly thicker than a child's. It's a part of our body, like our eyes, that doesn't change much in size as we grow up. Even baby earrings can be worn by most adults, unless the adult ear lobe is especially thickened for some reason.
We wouldn't consider our penguin earrings, our toadstool earrings, our frog earrings or our giraffe earrings, for example. to be worn by adults, however, adults have purchased our children's amethyst cz drop earrings, our Rosaline pearl earrings, and our little cz stud earrings and many others, for themselves, on many occasions.
Children's bracelets and children's necklaces are obviously not going to work on adults however, any of our earrings should fit just fine. I wear them myself!