Big congrats!
Here are some names that complement Octavia:
Hermione (I like Honey or Minnie as a nn)
Persephone (Persy, Sephie or Poppy)
Xanthe
Claudia
Miranda
Lucinda
Beatrice
Tabitha
Camilla
Isadora
Theodora
Rosamund
Rosamund
Eugénie
Adelaide
Tallulah
Cressida
Delphine
Philippa
Liberty