I love [name_f]Margot[/name_f]. Most of the names I’d have suggested are already on here – I especially love [name_f]Amelie[/name_f] with [name_f]Norah[/name_f]. A few other suggestions…
[name_f]Ada[/name_f] - [name_f]Ada[/name_f] reminds me a lot of [name_f]Anna[/name_f] and it has the same vintage appeal that [name_f]Vera[/name_f] and [name_f]Dorothy[/name_f] do. [name_f]Ada[/name_f] [name_f]Lillian[/name_f] and [name_f]Ada[/name_f] [name_u]June[/name_u] are both very pretty.
[name_f]Alice[/name_f] – I think [name_f]Alice[/name_f] and [name_f]Norah[/name_f] are such perfect sister names. They are both sweet, timeless classics that suit all ages. [name_f]Alice[/name_f] is obviously easily recognizable but is #76 on the popularity charts, so not crazily popular. [name_f]Alice[/name_f] [name_f]Lillian[/name_f] is a nice combo and I don’t think I’ve ever seen it before.
[name_f]Amalia[/name_f] - [name_f]Ophelia[/name_f] reminds me of [name_f]Emilia[/name_f]/[name_f]Amelia[/name_f], but that name is so popular I decided to put [name_f]Amalia[/name_f] down instead. It has a lovely association for me to the song [name_f]Amalia[/name_f] by [name_f]Melody[/name_f] Gardot.
[name_f]Elodie[/name_f] - [name_f]Elodie[/name_f] isn’t even in the top 1,000, but it’s such a beautiful name. I’m not sure if it checks the box on being familiar, but it’s so pretty with [name_f]Norah[/name_f].
[name_f]Emmeline[/name_f] – [name_f]Emmeline[/name_f] feels a lot like [name_f]Bethany[/name_f] or [name_f]Natalie[/name_f] to me in that it has a soft sound to it and feels very sweet but also seems like it would age well. [name_f]Norah[/name_f] and [name_f]Emmeline[/name_f] are nice complements for each other. I like [name_f]Emmeline[/name_f] [name_u]June[/name_u].
[name_f]Imogen[/name_f] - I was really surprised to find out that [name_f]Imogen[/name_f] isn’t in the US top 1,000 –*it’s definitely a familiar name, at least to me. [name_f]Imogen[/name_f] has the same soft sound as many of your other names, at least to my ear.
[name_f]Isabelle[/name_f] - [name_f]Isabelle[/name_f] just seems so pretty with [name_f]Norah[/name_f] and [name_f]Isabelle[/name_f] [name_u]June[/name_u] is such a pretty combo. Obviously it’s familiar sounding, but not overly popular nowadays ([name_f]Isabel[/name_f] is at #145 and [name_f]Isabelle[/name_f] is at #103).
[name_f]Maisie[/name_f] - I was going to recommend the name [name_f]Daisy[/name_f], but it would’ve violated your husband’s rule about nouns 
[name_f]Maisie[/name_f] has the same sweet, soft sound as many of the other names on your list. [name_f]Maisie[/name_f] and [name_f]Norah[/name_f] sound so sweet together. It also reminds me of [name_f]Mabel[/name_f] and [name_f]Margot[/name_f]. It also has such a sweet meaning (pearl). [name_f]Maisie[/name_f] [name_u]June[/name_u] is a really lovely combo.
[name_f]Phoebe[/name_f] - thought you might like [name_f]Phoebe[/name_f] because of the Fi sound in [name_f]Fiona[/name_f] combined with the end of [name_f]Bethany[/name_f]/[name_f]Natalie[/name_f]/etc. [name_f]Phoebe[/name_f] is familiar but not too common – it’s at #316. [name_f]Phoebe[/name_f] and [name_f]Norah[/name_f] sound adorable together.
[name_f]Sylvie[/name_f] - This borrows a few of the elements I saw reoccur in your list – vintage, sweet, with a soft sound. [name_f]Sylvie[/name_f] is easily recognizable and I don’t know if anyone would have trouble spelling it but it’s barely in the top 1,000. I think both [name_f]Sylvie[/name_f] [name_u]June[/name_u] and [name_f]Sylvie[/name_f] [name_f]Lillian[/name_f] could work.
Good luck!