I met a girl called Sassy the other day. Might be short for something but still - you can't get a sassier name than Sassy!
Otherwise:
Bronte, Coco, Cassia, Carmen, Darcey, Dakota, Eden, Effie, Fallon, Faith, Giselle, Halle, Harper, India, Jessamy, Jodie, Kendall, Kayla, Lola, Livia, Lyla, Leona, Macey, Morgan, Mika, Nicole, Nina, Nyah, Nia, Noa, Polly, Quinn, Riley, Romy, Rowan, Sylvie, Sorrel, Tegan, Taryn, Verity, Xanthe, Zia, Zillah