[name_f]Sienna[/name_f], [name_f]Leonora[/name_f], [name_f]Louisa[/name_f], [name_f]Lillian[/name_f], [name_f]Evelina[/name_f] or [name_f]Adela[/name_f]?
Thanks 
I think these are all grand names in their own rights, but all in very different styles. I don’t know if your [name_f]Amelia[/name_f] has any nicknames, but to me, lots of these potential sister names are very nickname-able, so I would consider that quite heavily. [name_m]Even[/name_m] if you don’t plan on nicknaming her, other people may throughout her life, so if there’s a nickname you hate, bear in mind people might call her that.
[name_f]Sienna[/name_f] - probable the least nickname-able, maybe [name_f]Annie[/name_f]?
[name_f]Leonora[/name_f] - [name_m]Leo[/name_m], [name_f]Nora[/name_f], [name_f]Lea[/name_f]
[name_f]Louisa[/name_f] - [name_u]Lou[/name_u], [name_m]Louie[/name_m]
[name_f]Lillian[/name_f] - [name_f]Lily[/name_f], [name_f]Anne[/name_f], [name_f]Annie[/name_f]
[name_f]Evelina[/name_f] - [name_f]Eve[/name_f], [name_f]Evie[/name_f], [name_f]Lina[/name_f], [name_f]Elin[/name_f]
[name_f]Adela[/name_f] - [name_f]Adele[/name_f], [name_f]Addie[/name_f], [name_f]Della[/name_f]
Some other names I like with [name_f]Amelia[/name_f]:
[name_f]Arabella[/name_f]
[name_f]Audrey[/name_f]
[name_f]Cosette[/name_f]
[name_f]Evangeline[/name_f]
[name_f]Lydia[/name_f]
[name_f]Scarlett[/name_f]
My favourites on your list are [name_f]Sienna[/name_f], [name_f]Louisa[/name_f], and [name_f]Adela[/name_f]. I also like [name_u]Eloise[/name_u] and [name_f]Esme[/name_f] for you.
[name_f]Lillian[/name_f] and [name_f]Louisa[/name_f] are my favorites.
I like [name_f]Lillian[/name_f] best. It goes well with [name_f]Amelia[/name_f] and I like that it doesn’t also end with an a.
It might depend on if you call [name_f]Amelia[/name_f] by a nickname and if you’d use a nickname for any of your suggestions.
[name_f]Adela[/name_f] matches well in my opinion. I also love [name_f]Evelina[/name_f].
My favourites with [name_f]Amelia[/name_f] are [name_f]Sienna[/name_f], [name_f]Lillian[/name_f] and [name_f]Adela[/name_f]
[name_m]Hi[/name_m]! I think that from your choices [name_f]Amelia[/name_f] fits perfectly alongside [name_f]Evalina[/name_f] and [name_f]Leonora[/name_f]. They sound fresh and pretty without the ‘trying too hard to be different’ vibe. I do stress though, that [name_f]Amelia[/name_f] and [name_f]Adela[/name_f] sound a tad too similiar for siblings, imo.