Your boys names don’t seem so far apart..
How about Jude, Rufus, Leon, Jerome, Kester, Guy, Jethro, Lorne, Caleb, Francis, Rafe, Lucas, Linus, Magnus, Elijah nn Eli, Noah, Ronan, Jonah, Jonas, Aaron, Cassian, Alistair, Nathanial nn Nate, Gabriel nn Gabe, Tobias
Girls are a bit more of a gap
How about Aphra, Freya, Stella / Estella, Lois, Astra, Ines, Cassia, Cleo, Leonie, Esther, Elowen, Ffion, Aster, Seren, Catrin, Lowenna, Annis, Annalise, Meredith, Adela, Frances, Rosanagh, Ismene, Ione