The Uptown Charm Maxi Dress

It sounds elevated without being overdone, and it works beautifully regardless of whether the actual color is mocha, beige, or another neutral.
My runner-up would be The Leopard Luxe Tiered Maxi Dress, especially if we want customers searching for leopard print dresses to recognize it immediately.
I'm leaning toward names that are elegant, memorable, and not overly faith-themed, since the boutique already has such a beautiful modest-fashion identity.