[name_f]Elizabeth[/name_f] and [name_f]Isabella[/name_f] are both beautiful! I personally wouldn’t do it but I do find it more interesting than someone using the same name multiple times (I know a family that gave their three daughters the same middle). [name_f]Isabella[/name_f] I will always love, but if you want to get away from a variation of [name_f]Elizabeth[/name_f], what about:
[name_f]Arabella[/name_f]
[name_f]Mirabella[/name_f] or [name_f]Mirabel[/name_f]
[name_f]Annabel[/name_f] or [name_f]Annabella[/name_f]
[name_f]Christabel[/name_f]
[name_f]Bella[/name_f]
[name_m]Bellamy[/name_m]
[name_f]Bellatrix[/name_f] (maybe not the best given the hp character, but pretty if you can separate it from the character!)
[name_f]Isaura[/name_f]
[name_f]Louisa[/name_f]
Ysaline or [name_f]Isaline[/name_f] (or even Isolina)
[name_f]Isolde[/name_f]
[name_f]Ismerie[/name_f]
[name_f]Esme[/name_f]
[name_f]Isla[/name_f]
[name_f]Felicity[/name_f] (has the el sound of [name_f]Bella[/name_f] plus I could see [name_f]Izzy[/name_f] also being a stretchy nickname for her, [name_f]Ella[/name_f], [name_f]Ellie[/name_f], [name_f]Cece[/name_f], [name_f]Lettie[/name_f], etc., also could be nicknames, or [name_f]Flick[/name_f], Flicka, or Fliss (I’m not fond of those but those were the first nn options I heard when I first came across Felicity)
[name_m]Or[/name_m] even another romantic, Latin-related name like:
[name_f]Cecilia[/name_f]
Juliet/Juliana
[name_f]Valeria[/name_f] or [name_f]Valencia[/name_f] or [name_f]Valentina[/name_f]
[name_f]Natalia[/name_f]
[name_f]Evelina[/name_f]
[name_f]Carolina[/name_f]
[name_f]Luciana[/name_f]
[name_f]Mariana[/name_f]
[name_f]Marina[/name_f]
[name_f]Fiorella[/name_f]
[name_f]Georgina[/name_f]
[name_f]Helena[/name_f] (so sweet with Lilly!)
[name_f]Emilia[/name_f]
[name_f]Sofia[/name_f]
[name_f]Gabriella[/name_f]
[name_f]Leonor[/name_f]
[name_f]Philomena[/name_f]
Good luck!