I’m late to this, but I empathize. My sister still likes to laugh about the time I, who was legal to drink, got carded and she, who is 5 years younger than me and was too young, did not. The first couple semesters I taught at university, I made sure to get to class early on the first day to get to know students, and as starting time approached, some one suggested I should sit down/move my books so I wouldn’t be in the way when the prof arrived. In each of those semesters, once classes were underway and they saw my knowledge and were required to accept my judgement, the problem generally disappeared (except for a couple hot-for-teacher types). So I think your demeanor and playing your role well are very important.
I’d say avoid the many styles popular now that borrow from young styles: chucks are not your friends, and neither are hoodies. I agree with the comments above that come down to avoiding extra “poofiness”, so no bows, frilly lace, etc. But then I think you also want to avoid things that highlight your body.
In the casual way of dressing during the pandemic, I think that leaves ankle boots, straight cuts of pants (not flared or “skinnies”), tunic-style tops, and toppers that tend toward “elegant” cuts.
I don’t think make-up is likely to help. We’ve all seen high school girls who cake it on. Wear what’s comfortable, but more does not equate to older.
I agree with the above that looking pulled-together can help, but would caution that if you go all the way to “precious”, then it backfires and you look like a babydoll someone has dressed up.
I agree with the above poster who mentioned that sweet innocence is part of the appeal of a bride, and would add that as long as the person you are marrying knows you as an adult woman, then it’s all good. With no idea of your current situation, I will add that it’s possible you won’t be so worried about looking young by the time you do get married.
