I like Leia and would say it lay-a.
Not keen on Clarabelle, though I don't think Clara is a problematic nickname just because of the Clarra/Clahra/Clairea possibilities with Clarabelle. Kitty doesn't sound like Katherine, Maggie like Margaret or Betsy like Elizabeth but they still get used.
Alternatives that aren't overly popular, I dont think:
Lena, Lyla, Lyra, Lara, Lana, Leona, Livia, Amaya, Anaya, Daya, Faye, Faith, Inaya, Jay, Kaia, Maia, Nyah, Nia, Raya, Ria, Rae, Tia, Thea, Zia
Arielle, Christabel, Clarissa, Cassandra, Cordelia, Giselle, Isadora, Mirabelle, Pandora, Rosabelle, Saskia, Tallulah, Vanessa