[name_u]Everett[/name_u], [name_f]Genevieve[/name_f] and [name_f]Sylvia[/name_f] gets my vote here! Such very beautiful names, both as a group and separately.
These are my thoughts:
Option GA: [name_f]Genevieve[/name_f] and [name_f]Alexandra[/name_f] - balanced in terms of length, but also quite different in sound, looks, and even style to an extent (what with [name_f]Alexandra[/name_f] being rather popular now).
Option GS: [name_f]Genevieve[/name_f] and [name_f]Sylvia[/name_f] - very balanced in terms of sound, looks, style, and they flow so well wonderfully together.
Plus, [name_f]Evie[/name_f] and [name_f]Sylvie[/name_f]? This would be SO sweet!
“[name_f]Alexandra[/name_f] - is it too popular? There are lots of little [name_u]Lexie[/name_u]'s out there now with the ongoing popularity of [name_u]Alexis[/name_u].”
~I think that is perhaps an issue here - she would bump into many fellow [name_u]Alex[/name_u]'s/[name_u]Lexi/name_u’s, etc, while her twin won’t simultaneously bump into lots of Genevieves! (Beautiful and all as it is, [name_f]Alexandra[/name_f]'s popularity is a slight drawback.)
“Does it match the other two vintage choices that were popular 100 years ago?”
~[name_f]Alexandra[/name_f] does match in a historical viewpoint, but I would also say that today [name_f]Alexandra[/name_f] instantly sounds more ‘modern’ than [name_f]Sylvia[/name_f], due to all the young Alexandras/Alexas/[name_u]Alex[/name_u]'s.
“[name_f]Sylvia[/name_f] - checks the vintage box, but does it just feel too ‘old lady’ still?”
~ It is absolutely not, in any way, too ‘old lady’!
“And is it equally “weighted” to [name_f]Genevieve[/name_f]?”
Definitely.
Option GJ: [name_f]Genevieve[/name_f] and [name_f]Josephine[/name_f] - Would they become [name_f]Jenny[/name_f] & [name_u]Josie[/name_u]? [name_u]Gene[/name_u] and [name_u]Jo[/name_u]?!
I can definitely see why this pairing appeals to you, but … Please don’t go with this option! If I was the twin named [name_f]Josephine[/name_f], I would be so, so jealous of my twin’s name, haha! I also think they are just a little too alike in sound; too “matchy”, if you will. I like the slight contrast the other options provide, and I believe it’s nice for twins to be truly individual, names and all.
So! I think [name_f]Sylvia[/name_f] flows so well with [name_f]Genevieve[/name_f] (and [name_u]Everett[/name_u]), I love this sibset, and the “v” connection. [name_f]Alexandra[/name_f] would be my second choice.
(I just thought, do you maybe also like the sound of [name_u]Everett[/name_u], [name_f]Genevieve[/name_f] and [name_f]Vivienne[/name_f]? [name_m]Just[/name_m] another idea! Both girls’ names would be [name_m]French[/name_m], the three names have V in them, and I think they sound lovely together. But maybe you’re not a fan of [name_f]Vivienne[/name_f]!)
I hope this is helpful, I know I’ve written a slightly lengthy response. Best of luck deciding - let us know what you choose!