[name_f]Anna[/name_f]-[name_f]Sofia[/name_f] is impeccable. There is something so, so right about those two names together. I would not pair her with [name_f]Ella[/name_f]-[name_f]Maria[/name_f] though it could be done. The coordination is just too much for me. It tends to highlight their similarities rather than their own special qualities. I would avoid another double name in the sibling set unless it’s the other gender.
I think the difficulty pairing sisters with [name_f]Anna[/name_f]-[name_f]Sofia[/name_f] is finding names that don’t sound too similar and also match her presence. [name_f]Anna[/name_f]-[name_f]Sofia[/name_f] has a lot of components that could easily overwhelm or wash out a shorter sibling name. So I think it’s best to look for longer names with hard letters and distinct vowel sounds if possible.
[name_f]Elodie[/name_f], [name_f]Victoria[/name_f], [name_f]Cosima[/name_f], [name_f]Natalia[/name_f], [name_f]Marita[/name_f], [name_f]Diana[/name_f], [name_f]Viola[/name_f], [name_f]Gabriella[/name_f], [name_f]Adriana[/name_f], [name_f]Valentina[/name_f], [name_f]Matilda[/name_f], [name_f]Henrietta[/name_f], [name_f]Freya[/name_f], [name_f]Noemi[/name_f], [name_u]Vivian[/name_u], [name_f]Estella[/name_f], [name_f]Noelle[/name_f], [name_f]Miriam[/name_f], [name_f]Juliana[/name_f], [name_f]Teresa[/name_f], [name_f]Camilla[/name_f], [name_f]Lydia[/name_f], [name_f]Veronika[/name_f], [name_f]Magdalena[/name_f], [name_f]Felicia[/name_f], [name_f]Cecilia[/name_f], [name_f]Helena[/name_f], Fransiska, [name_f]Katrina[/name_f], [name_f]Elvira[/name_f]
I think you have a lot more freedom with brothers because they’re unlikely to share the same ending as [name_f]Anna[/name_f]-[name_f]Sofia[/name_f] or sound too similar. I think you could choose a double name here with [name_m]Jon[/name_m]/[name_m]John[/name_m], [name_m]Paul[/name_m] or [name_m]David[/name_m] etcetera. A lot of traditional male names are accessible across the globe and would complement [name_f]Anna[/name_f]-[name_f]Sophia[/name_f] very well.
[name_u]Theo[/name_u], [name_m]Gabriel[/name_m], [name_m]Enzo[/name_m], [name_m]Felix[/name_m], [name_m]Simon[/name_m], [name_m]Emil[/name_m], [name_m]Nikolas[/name_m]/[name_u]Niko[/name_u], [name_m]Adam[/name_m], [name_m]Milo[/name_m], [name_m]Otto[/name_m], [name_m]Robert[/name_m], [name_m]Leo[/name_m], [name_m]Oliver[/name_m], [name_m]Tomas[/name_m], [name_m]Markus[/name_m], [name_m]William[/name_m], [name_m]Oscar[/name_m], [name_m]Rafael[/name_m], [name_m]Matteo[/name_m], [name_m]Benjamin[/name_m], [name_m]Samuel[/name_m], [name_m]Anton[/name_m], [name_m]Julius[/name_m], [name_m]Hugo[/name_m], [name_u]August[/name_u], [name_m]Dimitri[/name_m], [name_m]Immanuel[/name_m], [name_m]Linus[/name_m], [name_m]Vincent[/name_m], [name_m]Stefan[/name_m], [name_m]Mikael[/name_m]/[name_u]Mika[/name_u], [name_m]Sebastian[/name_m]