Adelaide or Audrey - I like both a lot but I LOVE Audrey. It's one of my all time favorites!
Camilla - It's ok.
Candace - NMS. Don't like potential nn Candy.
Charlotte - Like!
Eleni or Helena - Out of these two, Helena, but I'm not a huge fan.
Elise - Like.
Evangeline - Sorry, I don't see the appeal of this name.
Genevieve - Like but NMS.
Georgia - It's ok.
Giselle - Not a huge fan.
Grace - Overdone.
Josephine - Like a lot!
Katerina - Nice name but NMS.
Lydia - Like.
Magdalena - I have a soft spot for this name, it's H's 98 year old grandma's name :) She goes by Lena.
Maria - It's ok.
Margot - Like!
Miriam - NMS.
Nora - Nice but I think it's getting super popular (as a given name and nn).
Penelope - Like!
Priscilla - Don't like at all.
Rosamund - NMS.
Sonia - Nice name but not a favorite.
Sophie - Meh.
Sylvia - NMS.
Tamsin - Don't like.
Violet - Like.
Oh wow! This ones really difficult.
Clara, Lucy, Anna, Julia and...
My choices would be:
What I think would fit best with Clara, Lucy, Anna, and Julia:
I love the warmth, elegance and simplicity of your top four names. Anna, Clara, Julia and Lucy are all incredibly beautiful.
These are the ten I think fits in the best (they've all got that warm cosiness):
Camilla - sweet, charming and powerful at the same time.
Charlotte - classic. I really like Charlotte, it's one of those names I can't imagine anyone not liking.
Giselle - easily my favourite of your names. Giselle is an exquisite beauty, mythical and magical. I love it.
Helena - so lovely, and filled with ties to literature, mythology and also one of my favourite actresses.
Josephine - I know a lot of people here don't like this, but I find Josephine alluring, feminine, lithe and breathtaking. Like a morning in early summer by the seaside.
Maria - beautiful and simple. Much more appealing than Mary and Marie.
Sonia - warm, full of quirkiness and charm. I can't imagine a person named Sonia not being the absolute sweetest thing.
Sophie - this is an incredible name. It's sweet, beautiful,
Sylvia - ooh, Sylvia. Forest nymph like, and yet queenly.
Tamsin - happy name! Tamsin gives me the same feeling as Sonia, knitted jumpers and bags shaped as animals and nails painted in different colours.
I also really love Penelope and Rosamund, but to me they have a very different feel than the rest of your names.
My favourite three to go on your list: Sonia, Tamsin and Maria. And Helena too.
From your list, I absolutely love:
I really like Clara, Lucy, Anna and Julia. So simple, classic and pretty. Of your list, I think Audrey, Lydia. Nora, Sylvia, Elise and Margot and be the best match for a top ten, but those aren't necessarily my favourites.
Adelaide (prefer it to Audrey, though that is lovely too and would perhaps fit with your other choices more)
Elise (Whilst not a personal favourite, I feel like this fits well with your other names.)
Margot (see above)
Miriam (Crushing on this right now, with nn Mim!)
Eleni (prefer this to Helena, as Helena has pronunciation issues)
Penelope (I worry it's a little trendy though)
Violet (see above)
Tamsin (But please don't use the nn Tammy!)
Candace (Does not have the class of your other choices)
Charlotte (Just seems very predictable to me. I also grew up with a lot of Charlottes so it seems very 90s)
Evangeline (overly frilly, in my opinion)
Genevieve (see above, plus pronunciation issues)
Georgia (Also quite predictable)
Giselle (unpleasant sound, to my ears)
Grace (Another predictable choice, I know so many little Graces)
Priscilla (The Priss sound is off-putting)
Sonia (Dislike this because of a character in a soap here)
Sophie (Another one where I just feel it has been overused, though I think it may be less common in the US than the UK)
Hope that was helpful! I thought my reasons for ruling names out might be helpful for you as you try to narrow down :)