18-year-old girls are still little girls, but girls at this age already have their own personalities.
I think the host may be worried that giving some dolls that little girls like will make 18-year-old girls feel redundant, but the host can rest assured that no matter how old a girl is, she will not reject these things. However, I suggest that the host should give something else. Girls of this age are usually in school, so you can give stationery, Korean-style school bags, pens, etc. Or in terms of clothing, some bracelets and ornaments, or a beautiful dress are all good choices, which are very suitable for girls who love beauty at this age.
But girls of this age are not suitable for excessive dressing themselves up. Natural innocence is the best. The host can give her a more exquisite makeup mirror. Give her a feeling that she can understand her own beauty, but not too much decoration. The pattern of the mirror can be a little cute and girly. It is definitely a beautiful and practical gift.