Congratulations! I love your daughters names they go together really well! From your girls list I really like Marin, Verity, Posey and Petra! I love them all, by the looks of it we have similar name tastes.
From your boys list I love Elias and Luca. I've only once seen a boy named Joss, and never heard it before and thought it was very unusual, I think it would work well with your daughters names too. Although Joss and Cross from Crossman do rhyme, so that's another thing to think of.
Here are a few names I think could work well with Cora and Vesper.
Medi (It was the first name that came to mind when I saw September sibling, it means September in Welsh and it's not uncommon where I live. It's pronounced Mehd-ee, and I think it's pretty and works well with Cora and Vesper)
@bethlow -- I do like Eamon, very much, but DH isn't a fan. So sad.
Milo I love, but it belongs to the cat!
Everett is delightful but is too close to DH's name
Ezra is a great name, but will always be my jerk-face old boss. Ruined forever.
Merritt isn't one I'd heard, and I like it! I'll have to ask DH what he thinks. Thanks!!
I also like Felicity from your siggy. I haven't thought of it since my American Girl days.
Oh I love your daughters names. Cora and Vesper are stunning together, I think you have your work cut out for you to find an equally special name.
I really like pp's suggestion of Merritt for a boy - I also think that Alvar, Benedict, Orsino or Edwin could be good matches.
For girls I think something familiar but underused would be a nice choice. Elspeth, Iris, Aurelia or Tabitha would probably be on the top of my list with your girls names.
I posted this in another thread but you might not see it there. I didn't mean to freak you out - rather congratulate you. I have a brother very close in age to myself and it has been a wonderful experience.
I LOVE Marin... it's one of those hidden gems. Josephine is also quite great. Elias has long been my fav boys name (unfortunately the husband doesn't agree). Guess nothing ending with a T...
Eveline (like the James Joyce poem)
Roxana (Roxy is soooo cute)
Quentin (in love, but doesn't go with Crossman)
Roman (also, not with Crossman)
Keaton (ditto on Crossman)
Chayton (also not with Crossman)
Orion (not with Crossman)
Dear @Philomena. My deepest apologies. I'm afraid I let all the fakery talk, my insecurities and those darned pregnancy hormones run away with me. I hope our babes fare as well as you and your brother. No if only mama could keep her wits...
Thank you all for the suggestions. My lists have already doubled in size! Now for the hard work of deciding. Luckily we still have time! I'm sure I'll have plenty of requests for more suggestions and opinions soon enough.
I hope the weather is as nice where you are as it is here today!
My first thoughts were Eleri and Pietra/Pieta, which I slightly prefer to Petra (but only slightly!)
Cora, Vesper and Apolline/Apolonia
Cora, Vesper and Areia (means battleworthy, one of the titles of Athena)
Cora, Vesper and Aureline
Cora, Vesper and Demetria
Cora, Vesper and Elatine
Cora, Vesper and Elettra
Cora, Vesper and Elspeth
Cora, Vesper and Florence
Cora, Vesper and Ginevra
Cora, Vesper and Helaine/Elaine
Cora, Vesper and Idalia
Cora, Vesper and Ilaria
Cora, Vesper and Mabel
Cora, Vesper and Magdalena
Cora, Vesper and Maud
Cora, Vesper and Milena
Cora, Vesper and Minerva
Cora, Vesper and Mirin
Cora, Vesper and Olwen
Cora, Vesper and Orpha
Cora, Vesper and Quilla
Cora, Vesper and Rosemary
Cora, Vesper and Rue
Cora, Vesper and Seren
Cora, Vesper and Sylvia
Cora, Vesper and Tamsin
Cora, Vesper and Tessera
Cora, Vesper and Twila
Hope you like at least some of these names - good luck!