Alexis, Astrid, Addison, Ashlynn, Brooke, Bethan, Bridget, Claire, Coral, Carmen, Camryn, Cerys, Deborah, Diane, Erin, Eden, Esther, Edith, Fern, Frances, Faith, Genesis, Giselle, Hope, Hadley, Harper, Hayden, Hero, Hesther, Hannah, Hazel, Iris, Jordan, Jayden, Janet, Kaitlyn, Katrin, Karen, Kiran, Lauren, Lois, Lillian, Megan, Morgan, Madison, Merryn, Miriam, Nadine, Opal, Peyton, Payson, Paris, Piper, Quinn, Reagan, Robyn, Rachel, Ruth, Shannon, Seren, Sorrell, Taylor, Tegan, Tess, Violet, Willow, Xanthe, Yasmin, Zainab.
I think it's something to do with them mostly not ending in a,ee,i, o or y that makes them sound less 'girly'