ooo,[name_f]Cordelia[/name_f]! I love that name!
[name_f]Cordelia[/name_f]&[name_f]Clementine[/name_f] ([name_f]Cora[/name_f] & [name_f]Emmy[/name_f])
[name_f]Cordelia[/name_f]&[name_f]Rosie[/name_f]
[name_f]Cordelia[/name_f]&[name_f]Katelyn[/name_f]
[name_f]Cordelia[/name_f]&[name_f]Ella[/name_f]
[name_f]Cordelia[/name_f]&[name_f]Romilly[/name_f]
[name_f]Cordelia[/name_f]&[name_f]Savanah[/name_f]
[name_f]Cordelia[/name_f] and [name_f]Winona[/name_f] or [name_f]Cora[/name_f] and [name_u]Win[/name_u]/[name_f]Winnie[/name_f].
[name_f]Cordelia[/name_f] and Godeleva. [name_f]Cora[/name_f] and [name_f]Della[/name_f] or [name_f]Cora[/name_f] and [name_f]Eva[/name_f].
What ABSOLUTELY GORGEOUS Names your Children have!! [name_f]Cordelia[/name_f] is my ALL TIME FAVOURITE NAME!! SUCH a hard Name to match in style, feel, sound, look etc, but it’s so important to give BOTH Twins an equally precious Name!
I have loved a number of people’s suggestions, especially:
[name_f]Arabella[/name_f] (my own Daughter’s Name from back when it was still as rare as [name_f]Cordelia[/name_f])
[name_f]Mirabelle[/name_f]/a*
[name_f]Beatrice[/name_f]
[name_f]Emmeline[/name_f] (I prefer Emmelina)
[name_f]Lorelei[/name_f]
[name_f]Guinevere[/name_f]
[name_f]Amelie[/name_f]
[name_f]Adelaide[/name_f]
[name_f]Rosamund[/name_f] (honestly don’t think you’ll find too many people pronouncing it the original [name_m]German[/name_m] way, unfortunately)
[name_f]Florence[/name_f]
[name_f]Josephine[/name_f]
[name_f]Delphine[/name_f]
[name_f]Dulcinea[/name_f]
[name_f]Evangeline[/name_f]*
[name_f]Evelina[/name_f]
[name_f]Genevieve[/name_f]
[name_f]Seraphina[/name_f]
[name_f]Verity[/name_f]
[name_f]Rosalie[/name_f]
[name_f]Rosalind[/name_f]
[name_f]Marigold[/name_f]
[name_f]Philomena[/name_f]
[name_f]Primrose[/name_f]
[name_f]Ottilie[/name_f] (I am Australian too and have known several little Ottilies over the years and their Names were always pronounced O (as in [name_f]Opera[/name_f]) [name_m]Ti[/name_m] [name_u]Lee[/name_u]. They went by the gorgeous Nicknames [name_f]Lottie[/name_f] and [name_f]Tillie[/name_f]!)
[name_f]Clementine[/name_f] ([name_f]Minty[/name_f] would be an adorable Nickname!)
My additional suggestions (at long last, sorry) are:
[name_u]Florentine[/name_u]/[name_f]Florentina[/name_f]
Florimel
Melusina
[name_f]Lucina[/name_f]/[name_f]Lucinda[/name_f]
[name_f]Melisande[/name_f]
[name_f]Mimosa[/name_f]
[name_f]Amaryllis[/name_f]
[name_u]Damaris[/name_u]
[name_f]Calliope[/name_f]
[name_f]Thalia[/name_f]
[name_f]Laetitia[/name_f]/[name_f]Letitia[/name_f] (with the gorgeous Nickname [name_f]Lettie[/name_f]!)
[name_f]Lieselotte[/name_f] (with the Nickname [name_f]Lottie[/name_f] that you love.)
Edelweiss (with the Nickname [name_f]Edie[/name_f] that you love.)
Personally, if they were my precious Twins, I would go with:
[name_f]Cordelia[/name_f] [name_f]Frances[/name_f] and Melusina [name_f]Eliza[/name_f]
“[name_f]Cora[/name_f] and Lusi”
Or
[name_f]Cordelia[/name_f] [name_f]Frances[/name_f] and [name_f]Seraphina[/name_f] [name_f]Eliza[/name_f]
“[name_f]Cora[/name_f] and [name_m]Seraph[/name_m]”
Phew! [name_f]Hope[/name_f] I/we have helped! Please let us know what you decide! 
Oh okay haha sorry. I love [name_f]Henrietta[/name_f] then, I don’t think it matters if your little boys middle name is [name_m]Henry[/name_m].
[name_f]Henrietta[/name_f] and [name_f]Cordelia[/name_f] - both end in an ‘a’ sound which could be nice for twins without being to matchy matchy
[name_f]Hattie[/name_f] and [name_f]Cora[/name_f], is very sweet.
I don’t think [name_f]Rose[/name_f] is to common at all.
I love the name [name_f]Ottilie[/name_f] and would use nn. [name_f]Lottie[/name_f] also nn. [name_f]Tillie[/name_f] would work as well I would pronounce it Oh-tillie. It is very different, which is nice, I don’t think our accent would butcher it (which can deffs happen with an aussie accent and some names lol).
[name_f]Lottie[/name_f] and [name_f]Cora[/name_f] sounds very cute
What about [name_f]Anastasia[/name_f] ([name_f]Ana[/name_f]), [name_f]Estella[/name_f] ([name_f]Stella[/name_f], stell) or [name_u]Evelyn[/name_u] ([name_f]Eve[/name_f]), [name_f]Tea[/name_f], [name_f]Maren[/name_f]? I am a twin! Good luck!! Also my name is [name_f]Charlotte[/name_f], which I think is a great name but it might be too popular for your taste? Good luck!!
[name_f]Adelaide[/name_f]
[name_f]Aurora[/name_f]
[name_f]Adelia[/name_f]
[name_f]Elodie[/name_f]
[name_f]Adeline[/name_f]
[name_f]Evadne[/name_f]
[name_f]Ariadne[/name_f]