We’ve decided on the name [name_f]Aurelia[/name_f]. I love that it lends itself to various trends but this also makes it a bit difficult to narrow down a name for a sibling.
[name_f]Aurelia[/name_f] and [name_f]Letizia[/name_f] (Roman vibes)
or
[name_f]Aurelia[/name_f] and [name_f]Elowen[/name_f]? (English countryside vibes)
Would appreciate your votes or new ideas! (I don’t want a name that ends in an “ee” sound)
I like the [name_f]Letizia[/name_f] option. I think it is important to have the meaning be very positive and attributional when one twin’s name means “the golden one”. I would do something like [name_f]Luciana[/name_f] meaning light, [name_f]Celeste[/name_f] meaning heaven or [name_f]Estella[/name_f] meaning star 
[name_f]Aurelia[/name_f] and [name_f]Elowen[/name_f] are gorgeous separately and together! I love the mix of Italian and Cornish and how, despite the fact they’re very different names, they somehow make, to me at least, quite a cohesive set. Other options:
[name_f]Aurelia[/name_f] and [name_f]Chiara[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Freya[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Astrid[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Clementine[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Maeve[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Ilaria[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Matilda[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Juno[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Luella[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Margot[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Claudia[/name_f]
[name_f]Aurelia[/name_f] and [name_u]Florence[/name_u]
[name_f]Aurelia[/name_f] and [name_f]Thea[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Primrose[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Stella[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Marigold[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Violet[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Bianca[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Giselle[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Allegra[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Beatrix[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Clara[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Eloise[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Isobel[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Harriet[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Delphine[/name_f]
I love [name_f]Aurelia[/name_f]!
I like both [name_f]Elowen[/name_f] and Letizia; I think I like [name_f]Elowen[/name_f] just a bit more but they are both so pretty!
I think [name_f]Iris[/name_f], [name_f]Imogen[/name_f], or [name_f]Estella[/name_f] sound like a sister to [name_f]Aurelia[/name_f] as well.
I prefer [name_f]Elowen[/name_f]! I think a name with a [name_u]Sun[/name_u] meaning like [name_f]Aurelia[/name_f] would go well.
[name_f]Aurelia[/name_f] & [name_f]Cressida[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Kiara[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Marisol[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Oriana[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Ostara[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Solana[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Sunniva[/name_f]
[name_u]Or[/name_u] a name with a [name_f]Moon[/name_f] meaning
[name_f]Aurelia[/name_f] & [name_f]Elara[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Evaluna[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Mahina[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Neoma[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Pandora[/name_f]
[name_f]Aurelia[/name_f] & [name_f]Stellaluna[/name_f]
Fav is [name_f]Aurelia[/name_f] and [name_f]Elowen[/name_f]! Like a medow of flowers
Other ideas
[name_f]Miranda[/name_f]
[name_f]Lavinia[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Elowen[/name_f] are gorgeous!!!
A couple of suggestions
[name_f]Aurelia[/name_f] and [name_f]Ginevra[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Carys[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Cressida[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Lavinia[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Viviana[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Primrose[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Letizia[/name_f] sound like perfection to me! 
Both names are on my own list (well, a different spelling for [name_f]Letizia[/name_f], but still) so I might be biased, but [name_f]Aurelia[/name_f] and [name_f]Letizia[/name_f] as sibset seem like a name nerd dream to me lol. Look and sound great together, have similar roman vibes as you mentioned, and their meaning is “golden” and “happiness”. [name_f]Elowen[/name_f] is lovely as well, but [name_f]Letizia[/name_f] is such a underused gem!
I prefer [name_f]Letizia[/name_f] out of your two options, but think [name_f]Aurelia[/name_f] and [name_f]Elowen[/name_f] flows better! Both lovely names, and I’d like to suggest [name_f]Luminosa[/name_f] as the meaning links to [name_f]Aurelia[/name_f]!
[name_f]Aurelia[/name_f] and [name_f]Elowen[/name_f] work great together!
I’m not a fan of either sorry!
But if you want to stick to Latin vibes what about [name_f]Aurelia[/name_f] and [name_f]Rosa[/name_f]
[name_f]Aurelia[/name_f] and viola (Vee ola) the Latin way also aurelia is gold and viola is purple 
Countryish vibe
[name_f]Aurelia[/name_f] and [name_f]Rosie[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Daisy[/name_f]
[name_f]Hope[/name_f] that helps
[name_f]Aurelia[/name_f] and [name_f]Elowen[/name_f] is so lovely
[name_f]Beatrice[/name_f]
[name_f]Tabitha[/name_f]
[name_f]Cordelia[/name_f]
[name_f]Cornelia[/name_f]
[name_f]Delilah[/name_f]
[name_f]Francine[/name_f]
The only twin for [name_f]Aurelia[/name_f] I’d want is [name_f]Aurora[/name_f]. Despite their similarity, they are a very fine pair to me.
[name_f]Aurelia[/name_f] [name_f]Frances[/name_f]
[name_f]Aurora[/name_f] [name_f]Sophia[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Letizia[/name_f] has my vote (The nicknames [name_f]Lettie[/name_f] of Tizzy are too cute to pass up)
I really like [name_f]Aurelia[/name_f] and [name_f]Letizia[/name_f] together.
Other ideas:
[name_f]Aurelia[/name_f] and [name_u]Antonia[/name_u]
[name_f]Aurelia[/name_f] and [name_f]Athena[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Atalanta[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Briseis[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Lavinia[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Maxima[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Tatiana[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Verina[/name_f]
[name_f]Aurelia[/name_f] and [name_f]Varina[/name_f]
I like both your options, but personally prefer [name_f]Elowen[/name_f]
Other ideas (sorry for repeats)
[name_f]Acacia[/name_f]
[name_f]Cressida[/name_f]
[name_f]Juliana[/name_f]
[name_f]Ophelia[/name_f]
[name_f]Camellia[/name_f]
[name_f]Callista[/name_f]
[name_f]Magnolia[/name_f]
[name_f]Marigold[/name_f]
[name_f]Sylvia[/name_f]
[name_f]Celestina[/name_f] / [name_f]Celestia[/name_f]
[name_f]Selena[/name_f] / [name_f]Selene[/name_f]
[name_f]Eliza[/name_f]
[name_f]Elara[/name_f]
[name_f]Rosalind[/name_f]
[name_f]Lucinda[/name_f]
[name_f]Vivia[/name_f]
[name_f]Eliora[/name_f]
[name_f]Helena[/name_f] / [name_f]Helene[/name_f]