Fern is okay. I'm not that keen but it's nice enough. I wouldn't associate with Fern Britton.
I prefer Lucy to Lucia but guess that's probably a bit common for your tastes.
Outside the top 100, unusual but not weird:
Anya, Ayla, Aubrey, Adele, Ariel, Aurora, Alannah, Anika, Anoushka, Briley, Bonnie, Celia, Cecily, Cassandra, Clarissa, Camilla, Cora, Cleo, Clea, Dora, Dana, Emery, Erica, Eden, Esther, Enya, Eilidh, Evadne, Eliana, Farrah, Fionhuala, Giselle, Genesis, Heather, Halle, Hayley, Ida, Iona, Jodie, Jade, Juliet, Jordan, Kiran, Kara, Lana, Luna, Lois, Leonie, Morgan, Miranda, Marissa, Maria, Nia, Nyah, Natasha, Philippa, Polly, Quinn, Ruth, Robyn, Sasha, Sadie, Seren, Stephanie, Talia, Tamsin, Verity, Xanthe, Yvette, Zia, Zillah.