You seem to like 3 syllable names - Abigail, Eleanor, Susannah - so I've tried to think of some others along those lines as well as some stylistically similar to those you mentioned.
Adelaide/Adeline ('Addie' instead of 'Abby')
Annabel
Camilla
Caroline
Cecily
Charlotte
Christina
Felicity
Florence
Francesca
Gabrielle ('Gabby' instead of 'Abby')
Georgina
Harriet
Imogen
Jessamy
Juliet
Louisa
Lucinda
Lydia
Matilda
Miranda
Phoebe
Rebecca
Rosamund
Serena
Sophia
If you want another cute nickname (along the lines of Abby and Ellie), consider names that lend themselves to nicknames: Aggie, Cassie, Franny, Izzy, Josie, Katie, Kitty, Lettie, Libby, Lottie, Lou, Millie, Penny, Polly, Rosie, Sadie, Tess, Tessie, Tillie, etc.
For you, I particularly like Eleanor, Samuel, and Felicity; Eleanor, Samuel, and Charlotte; Eleanor, Samuel, and Gabrielle; and Eleanor, Samuel, and Camilla. But Susannah is a great choice and if you love it, use it.