I like it. I'd assume a boy on first hearing it but I don't think that matters. When you see it written down, it's obviously a girl.
I love Aphra though; one of my favourite names and so underused.
Other ideas:
Astrid, Aya, Ada, Amaya, Ayla, Aria, April, Ariel, Bethan, Briar, Cleo, Cerys, Carys, Claire, Coco, Carmen, Dana, Devon, Etta, Enya, Elora, Fallon, Faith, Faye, Greta, Giselle, Hannah, Hope, Honor, Hero, Inez, Iona, Ida, Jessa, Juno, Jocelyn, Joy, Keira, Kyra, Liora, Livia, Leona, Lara, Lyra, Lena, Lois, Mala, Mara, Mina, Mila, Mika, Mabel, Nyah, Nova, Nora, Nina, Nesta, Orla, Opal, Piper, Pippa, Quinn, Rose, Rosa, Robyn, Rowan, Rhiann, Rivkah, Tamara, Thea, Taryn, Tegan, Una, Viola, Wren, Winter, Yusra, Zia, Zeryn