For girls, I wouldn’t use another G or H name unless you’re favourite but especially a G name because G/Gi/Gigi such a strong nickname for Georgia.
Of your three, I’d pick Cecily or Penelope so everyone has their own starting letter, ending sound but also complement each other. I like Norah too - it’s almost a smoosh of the other two which could go for or against!
Other girls you might like: Adelaide, Eliza, Beatrice, Beatrix, Louise, Florence, Edith, Camille, Bryony, Luella, Claire, Arabella, Romilly, Phoebe, Ruby, Imogen, Matilda, Xanthe, Ivy, Verity, Tabitha, Zoe.
For boys, Reuben or Alistair (or - better - the Scottish Alasdair) could work well and hold up to the girls’. I think Louis works too - but I prefer Louie (French/UK/Oz etc) pronunciation of Louis than Lewis (not sure where you are but presuming US bc of Todd!), And I really like Jasper but I might see if I can get a non G sound first. Todd somehow doesn’t go as well imo and neither does Jacob. See them as fitting better with other names & styles. But Hacob would be my pick of the two.
Other guys you might like: Edmund, Conrad, Oscar, Malcolm, Tobias, Sebastian, Felix, Benedict, Barnaby, Zachary, Xander, Stanley, Lachlan, Brooks, Rupert, Robin, Samuel, Westley/ Wesley, Frederick, Vincent, Anderson.
Hope this helps!