I know Camillas with siblings:
George
Oliver
Jemima
I like Annabel and Frederick best from your list.
Arabella, Araminta, Aurelia, Ariadne, Alicia, Anastasia, Antonia, Alexandra, Angelica, Amelia, Beatrice, Dorothea, Evangeline, Elizabeth, Erica, Eloise, Francesca, Felicity, Florence, Fenella, Fabia, Felicia, Georgina, Giovanna, Genevieve, Hermione, Harriet, Henrietta, Isabella, India, Imogen, Joanna, Jessica, Josephine, Juliette, Katherine, Lucinda, Lydia, Lorelai, Leandra, Miranda, Matilda, Madeleine, Marianna, Natalia, Natasha, Ophelia, Octavia, Philippa, Persephone, Phoebe, Rebecca, Rhiannon, Rosemary, Rosalie, Sophia, Seraphina, Saskia, Tamara, Victoria, Vanessa, Violet, Xanthe, Zara.
Alistair, Alexander, Angus, Benedict, Bartholemew, Cosmo, Caspian, Edward, Felix, Fergus, Fabian, Gregory, George, Harrison, Henry, Josiah, Jonathan, John, Lucian, Leo, Leonard, Montgomery, Maxwell, Matthew, Nathaniel, Nicholas, Oscar, Orlando, Ptolemy, Patrick, Quentin, Robert, Solomon, Sebastian, Timothy, Victor, William, Xavier, Zachary.