You have a really great list. You have excellent taste. When I thought I might be having girl twins the two I picked were Actually [name]Alice[/name] and [name]Caroline[/name]. They go great together, but I see you eliminated [name]Alice[/name] for a very understandable reason, though I’m also really sad to see [name]Jane[/name] go.
[name]Caroline[/name] - My favorite from your list of course. I love everything about [name]Caroline[/name].
[name]Charlotte[/name] - [name]Charlotte[/name] is also nice. Especially since you don’t seem like the to use [name]Charlie[/name] as a nickname.
[name]Elizabeth[/name] - Great history and a Wealth of nicknames.
[name]Georgia[/name] - A nice name, but I’ve never cared for it. I think of the state. Oddly enough I don’t have that problem for [name]Virginia[/name].
[name]Katherine[/name] - Same response as [name]Elizabeth[/name].
[name]Margaret[/name] -Same as [name]Elizabeth[/name] and [name]Katherine[/name].
[name]Martha[/name] - Hasn’t really warmed up for me. I can only see the old lady-ness of it.
Secretly I’ve always though [name]Charlotte[/name] and [name]Caroline[/name] would make cute twin names. They’re rooted in the same name, but sound completely different. I really like that. I think it’s Carolinus or something similar that was the original name, and [name]Caroline[/name] is the feminine form of that. [name]Charles[/name] is a variation of it, and [name]Charlotte[/name] is the feminine version of it. However since you want to avoid repeat initials you probably won’t like it, although they do not alliterate. Some people might disagree, and I can see why, but I really like them as a twin set.
The others I would pair together are [name]Elizabeth[/name], [name]Katherine[/name], and [name]Margaret[/name]. Mainly because they all have the same feel to me: Timeless classics with unlimited nicknames. [name]Liz[/name], [name]Lizzy[/name], [name]Beth[/name], [name]Libby[/name], [name]Betty[/name], [name]Betsy[/name], [name]Izzie[/name], [name]Liza[/name], [name]Bette[/name], [name]Ellie[/name], [name]Eliza[/name], [name]Elsa[/name]. [name]Katie[/name], [name]Kate[/name], [name]Kitty[/name], [name]Kay[/name], [name]Kit[/name], [name]Kat[/name], [name]Kathy[/name], [name]Karen[/name]. [name]Maggie[/name], [name]Margot[/name], [name]Greta[/name], [name]Peggy[/name], [name]Maisie[/name], [name]May[/name], [name]Daisy[/name], [name]Margie[/name], [name]Madge[/name], [name]Rita[/name], [name]Peg[/name], [name]Megan[/name], [name]Meg[/name].
My personal favorites would be:
[name]Betsy[/name], [name]Elsa[/name], [name]Eliza[/name]
[name]Kitty[/name], [name]Kay[/name], [name]Kate[/name]
[name]Greta[/name], [name]Margot[/name], [name]Maggie[/name], [name]May[/name], [name]Maisie[/name], [name]Daisy[/name], [name]Rita[/name]
So you can really shape those three into any kind of feel with nicknames. Also beware that you give your girls room to eventually decide they want different nicknames. I think I prefer [name]Katherine[/name] and [name]Margaret[/name], but [name]Elizabeth[/name] is wonderful as well. [name]Margaret[/name] is probably my favorite of all other than [name]Caroline[/name]. I could seriously have like six daughters with different [name]Margaret[/name] names and still be happy haha.