I quite like Honor but think it's perhaps a bit much as a pair wih Charity (although they will only be seen as a pair when they are children so it probably doesn't matter that much). Also, Honor Littlejohn sounds like a command sentence - 'honour little John'.
I'v never beeen sure if Honor counts as a virtue name or not because of the spelling or whether it has a different origin. But, even if it's not, it sounds so much like one that I'd avoid it. Whereas Felicity and Verity, despite being undoubtedly virtue names, seem better fits for Charity just because we don't tend to use those two names as abstract nouns in everyday conversation so they remain as purely names not both names and virtues.
Names that I think go with Charity without being themed/matchy:
Anne, Alice, Anastasia, Bronte, Daphne, Diana, Evangeline, Edith, Florence, Frances, Giselle, Gloria, Harriet, Iris, Josephine, Juliet, Jemima, Katherine, Kate, Lillian, Lucia, Larissa, Lydia, Martha, Marina, Nadine, Nadia, Pearl, Ruth, Rosemary, Sylvia, Stella, Theresa, Tamara, Ursula, Vivianne, Violet, Yolanda