I think [name_f]Calla[/name_f] and [name_f]Camille[/name_f] are just a bit too similar, but I really like [name_f]Sylvia[/name_f] with [name_f]Camille[/name_f]
I dont see an issue with [name_f]Calla[/name_f] and [name_f]Camille[/name_f] together. I think they make a good sibset.
I prefer [name_f]Sylvie[/name_f] with [name_f]Calla[/name_f]. My only association with [name_f]Suri[/name_f] is [name_m]Tom[/name_m] [name_f]Cruise[/name_f].
I do think they are a little too match-y for sisters, but they sound distinct enough. [name_f]Sylvie[/name_f] & [name_f]Calla[/name_f] or [name_f]Sylvie[/name_f] & [name_f]Camille[/name_f] would be lovely sister sets!
[name_f]Calla[/name_f] and [name_f]Camille[/name_f] do feel too close to me, but they’re not impossible. It’s not a clear cut one - while I wouldn’t choose them I think it’s fine to do it.
[name_f]Sylvie[/name_f] out of your other 2.