Coquette is a culmination of aesthetics that all incorporate feminine adolescence, including Lolita and nymphet. It is best described as the hyper-sexualization of feminine youth with a Victorian influence.

Historically, the aesthetic originated in the characterization of nymphet, a young girl who pursues older gentlemen. The aesthetic has evolved and shifted recently, and it is now more about the Victorian influence of sexy-but-delicate femininity 

Coquette fashion is hyper-feminine and seductively innocent. You will see a lot of lace, soft colors, ruffles, corsets, ribbons, bows, stockings, camis, and a youthful and delicate Victorian influence. It is still very much about sexualizing feminine innocence. Lana Del Rey has popularized the modern coquette aesthetic.