Josephine and:
Charlotte
[name_f]Rebecca[/name_f]
[name_f]Camilla[/name_f] (could also use [name_f]Callie[/name_f] as a nickname here)
[name_u]Vivian[/name_u]/Vivienne
[name_f]Elizabeth[/name_f]
[name_f]Catherine[/name_f]/Katherine
[name_f]Eleanor[/name_f]
[name_f]Theodora[/name_f]
[name_f]Penelope[/name_f]
Firstly congratulations on your twin girls 
I love the idea of [name_f]Josephine[/name_f] & [name_f]Emmeline[/name_f] that’s a great suggestion from @cactusgram
Other suggestions (count repeats as seconds)
Angeline ~ [name_f]Josephine[/name_f] & [name_f]Angeline[/name_f] ‘[name_u]Angie[/name_u]’
[name_f]Evangeline[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Evangeline[/name_f] ‘[name_f]Evie[/name_f]’
[name_f]Adeline[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Adeline[/name_f] ‘[name_f]Addie[/name_f]’
[name_f]Delphine[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Delphine[/name_f] ‘[name_f]Delphi[/name_f]’
[name_f]Clementine[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Clementine[/name_f] ‘[name_u]Clem[/name_u]’
[name_f]Alexandrine[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Alexandrine[/name_f] ‘[name_u]Lexi[/name_u]’
[name_f]Hermine[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Hermine[/name_f] ‘[name_f]Minnie[/name_f]’
[name_f]Ottoline[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Ottoline[/name_f] ‘Otti’
[name_f]Rosaline[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Rosaline[/name_f] ‘[name_f]Rosie[/name_f]’
[name_f]Coraline[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Coraline[/name_f] ‘[name_f]Cora[/name_f]’
[name_f]Evaline[/name_f] ~ [name_f]Josephine[/name_f] & [name_f]Evaline[/name_f] ‘[name_f]Evie[/name_f]’
[name_u]Valentine[/name_u] ~ [name_f]Josephine[/name_f] & [name_u]Valentine[/name_u] ‘[name_u]Vale[/name_u]’
Hope this helped
Josephine &…
Penelope nn [name_u]Penny[/name_u] or [name_f]Poppy[/name_f]
[name_f]Francesca[/name_f] nn [name_u]Fran[/name_u] or [name_u]Frankie[/name_u]
[name_f]Cordelia[/name_f] nn [name_u]Cory[/name_u] or [name_u]Del[/name_u]
[name_f]Regina[/name_f] nn [name_u]Reggie[/name_u]
[name_f]Louisa[/name_f] nn [name_u]Lou[/name_u]
I think [name_u]Lou[/name_u] & [name_u]Jo[/name_u] would be cute!
Hi there.
I love [name_f]Josephine[/name_f]! [name_f]Madeline[/name_f] would be lovely for her twin sister, but I’m totally w/you about [name_f]Maddie[/name_f]. What about [name_f]Maisy[/name_f]? I love [name_f]Madeline[/name_f] nn [name_f]Maisy[/name_f]. [name_f]Mally[/name_f] would be cute too. I also like [name_f]Callie[/name_f], but if you don’t like [name_f]Caroline[/name_f] you shouldn’t use it. [name_f]Do[/name_f] you like [name_f]Callista[/name_f]? [name_f]Calliope[/name_f]? [name_f]Camellia[/name_f]?
Sorry for any repeats, but here are a few more suggestions:
Adeline, but do you like [name_f]Addie[/name_f]? I think it’s cute, but so over done.
Adelaide…same issue.
Abigail
Coraline
Clementine
Cecilia
Cornelia
Dorothy
Dorothea
Elizabeth
Emmeline
Eloise
Estelle
Felicity
Gwendolen
Georgia
Georgina
Georgiana
Imogen
Katheirne
Lucienne
Louisa
Lilian
Magnolia
Penelope
Rosalie
Rosalind
Susanna
Sylvia
Theodora
Vivian
Hope this helps. 
[name_f]Josephine[/name_f] and [name_f]Veronica[/name_f]
Josephine and Cassandra
Josephine and Augusta
Josephine and Eleanor
Josephine and Audrey
Josephine and Miranda
Josephine and Therese
Josephine and Rebecca
Josephine and [name_f]Kathrine[/name_f] [name_f]Kathy[/name_f]/Kate
[name_f]Josephine[/name_f] and [name_f]Amanda[/name_f] [name_u]Mandy[/name_u]/Andy
[name_f]Josephine[/name_f] and [name_u]Maria[/name_u] [name_f]Mary[/name_f]/Marie