[name]Cecile[/name] - I think this spelling is prettier. [name]Love[/name] this name and I think this goes great with [name]Elise[/name] and [name]Marie[/name], but it makes [name]Clara[/name] seem like the odd not-French one out…
[name]Ellen[/name] - While I am a HUGE fan of [name]Ellen[/name] (it is my name, after all), I think it’s way too similar to [name]Elise[/name]
[name]Kate[/name] - Not as soft or vintage as the others
[name]Jane[/name]/[name]Jayne[/name] - I think [name]Jane[/name] works well with the rest. I think [name]Jayne[/name] looks weird, though.
[name]Anne[/name] - I actually think this is a GREAT addition, hits the French and vintage English marks, and nn [name]Annie[/name] gets you 2 syllables and 5 letters 
[name]Josie[/name] - too nicknamey for a name [name]IMO[/name]
[name]Heidi[/name] - a little more off the beaten track than the others, but I think it actually works.
[name]Lina[/name] - seems incomplete, like a nn for [name]Carolina[/name] or [name]Paulina[/name] or something
[name]Julia[/name] - another great addition
[name]Juliet[/name] - very pretty. While I think I like the sound of [name]Juliet[/name] better with the rest, I sort of miss the 5-letter look.
[name]Helen[/name] - [name]Tad[/name] close to [name]Elise[/name], but I think it works fine and sounds beautiful
[name]Corin[/name] - seems like a very different style from the others. Can’t get behind it…
[name]Monique[/name] - Too French and a tad too modern
[name]Belle[/name] - I think just [name]Belle[/name] might work okay, but I would worry about all the Bellas/Isabellas, etc.
[name]Willa[/name] - off your list anyway
[name]Rose[/name] - I think this would be beautiful and [name]Rosie[/name] get you the syllables/letters
[name]Adele[/name] - off your list (such a shame; thought it worked well)
[name]Leila[/name] - I don’t think this looks classic enough. The double L’s are trendy, too.
[name]Helene[/name] - I prefer [name]Helen[/name]. Eh-[name]LISE[/name], Ma-[name]REE[/name], He-LEEN, and poor odd-man-out, not-French-enough CLAR-uh.
[name]Elena[/name] (pronounced [name]Ellen[/name] - a or [name]Elayna[/name]) - way too close to [name]Elise[/name]
[name]Genevieve[/name] - love, think it fits, but seems way long compared to everyone else’s
[name]Olive[/name] - would have been cute, but a tad trendy
[name]Sadie[/name] - not quite sophisticated enough
[name]Faith[/name] - [name]Faith[/name] seems like a dated, country/twangy virtue name to me (thanks, [name]Faith[/name] [name]Hill[/name]?). I’d make it a no…
[name]Renee[/name] - suffers from what [name]Helene[/name] does, I guess, but I like it a lot more
[name]Lilah[/name] - on the trendy side, and I think since [name]Elise[/name] and [name]Clara[/name] have L sounds at the front, I’d be careful picking something that’s L-heavy on the front end again
[name]Giana[/name] - doesn’t fit others’ style
[name]Lydia[/name] - love this! I know it’s 3 syllables, but I think that spices things up without detracting from the 5 letter thing.
[name]Victoria[/name] - seems long and a little harsh-sounding against the others (I think it’s the V, T, and sharp C)
[name]Lillian[/name]/[name]Lilly[/name] - [name]Lilly[/name] seems really popular, but I think the style of these fits well
So my faves would be: [name]Anne[/name], [name]Julia[/name] and [name]Juliet[/name] (prefer [name]Julia[/name]), [name]Helen[/name], [name]Rose[/name], and [name]Lydia[/name]. Maybe you could mix some of the others in as middles ([name]Anne[/name] [name]Genevieve[/name], [name]Julia[/name] [name]Lillian[/name] or [name]Juliet[/name] [name]Cecile[/name], [name]Helen[/name] [name]Renee[/name], [name]Rose[/name] [name]Corinne[/name], or [name]Lydia[/name] [name]Olive[/name]).
[name]Michaela[/name] seems so much longer (and more popular) than the others, though I think this spelling (not created, but historically rooted) helps in fit with the vintage sibset. I guess sharing M with [name]Marie[/name] isn’t a bad thing, but there are so many names out there where she could have her own letter that I’d probably use them first. [name]Helen[/name] [name]Michaela[/name]?