preppy formal dresses Prom to Suit Your Aesthetic This dress style features an around the neck with pintucks at the chest and gathers at the waist making it perfect for any formal occasion. Preppy Homecoming Dresses - Shop

Or, for a much more affordable sock (in mercerized cotton), we like the Hansel from Basel Trouser Crew (womens)

The neckline may be higher, she may want to be more covered than the adult bridesmaids

A long sleeve adds modesty while keeping the outfit interesting and flowy

Azazie Retro Denim Style Women's Floral Dress ingshows Retro Denim Style Women's Floral Dress ProductNo SP24082205PH Fit Regular Sleeve Length Long Sleeve Design Elements Print Occasion Leisure,Outdoor,Home,Beach,Daily,Rain,Snow,Casual,Formal occasions,School Collar/Neckline V-neck Skirt Length Short Style Casual,Elegant,Bohemian,Vintage/Retro Material Polyes ingshows Summerlin Lace Top Maxi Dress | Black Western New Arrivals Tulle Corset Dress This Western New Arrivals Tulle Corset Dress expertly blends classic Western style with modern elegance