I love the name [name]Juliette[/name]! And you have some great options picked out for [name]Baby[/name] #2!
Here are my thoughts:
[name]Nora[/name] – “[name]Light[/name].” A little less feminissima than [name]Juliette[/name], but a great name regardless. No nn options.
[name]Fiona[/name] – “Fair.” A beautiful name but for some reason, I don’t see it with [name]Juliette[/name] as much as some of your other choices. Not really any nn options.
[name]Beatrice[/name] – “She who brings happiness.” I’ve never been able to get on board with this one. Despite the common Shakespearean ancestry, it seems rather stuffy compared to the airy [name]Juliette[/name]. Nns: [name]Bea[/name], [name]Tricia[/name]…
[name]Vivienne[/name] – “Life” Another name I’ve never personally gotten, but I think it pairs quite nicely with [name]Juliette[/name], particularly with this spelling. Cute nicknames: [name]Viva[/name], [name]Viv[/name], [name]Vi[/name], [name]Enna[/name]…
[name]Evangeline[/name] – “Bearer of good news.” Beautiful and darling, and lovely with [name]Juliette[/name]-- lots of good nickname options. [name]Eve[/name] and [name]Jules[/name] or [name]Lina[/name] and [name]Jules[/name] work well together as nicknames!
[name]Eleanor[/name] – “[name]Light[/name]” Beautiful and classy. I think [name]Eleanora[/name] would pair better with [name]Juliette[/name]. Could call her [name]Nora[/name] or [name]Ellie[/name]/[name]Ella[/name].
[name]Annabelle[/name] – “Loving.” a little earthier than [name]Juliette[/name] to my ears. Nns: [name]Belle[/name]/[name]Bella[/name], [name]Annie[/name]…
[name]Millicent[/name] – “Strong in work.” The only one of your names I’m not feeling at all, with or without [name]Juliette[/name]. I just can’t get images of evil stepmothers out of my head. I like the [name]Melisende[/name]/[name]Melisande[/name] form much better though! Nns: [name]Millie[/name]
[name]Genevieve[/name] – “White wave” Would you go with the French or the English pronunciation? Either way this name is gorgeous, feminine and light all at the same time, just like [name]Juliette[/name]. Would it bother you to repeat the “J” sound in your girls names? Some good nn options here too: [name]Gigi[/name], [name]Eve[/name], [name]Viva[/name], [name]Gen[/name]…
[name]Matilda[/name] --“Battle mighty.” Too heavy and stuffy for [name]Juliette[/name]. Nns: [name]Mattie[/name], [name]Tillie[/name]…
[name]Evelyn[/name] – “Desired.” [name]Love[/name] this with [name]Juliette[/name]. Nns: [name]Evie[/name], [name]Eve[/name], [name]Lyn[/name], [name]Ellie[/name]…
[name]Eloise[/name] – “Wide.” The meaning and the “weeze” sound has always thrown me off for this name. Otherwise, it flows quite nicely with [name]Juliette[/name]. Nns: [name]Ellie[/name]…
My favorites from your list:
[name]Juliette[/name] and [name]Eloise[/name]
[name]Juliette[/name] and [name]Genevieve[/name]
[name]Juliette[/name] and [name]Evelyn[/name]
[name]Juliette[/name] and [name]Evangeline[/name]*
[name]Juliette[/name] and [name]Vivienne[/name]
*= the winner! 
Good luck!