Looks like you and your husband have a pretty good list here!
I like [name_f]Esme[/name_f], [name_f]Sylvia[/name_f], and [name_f]Elsie[/name_f].
Maybe thinking of possible future sibling names will help you narrow it down. Would [name_f]Esme[/name_f] and [name_f]Elsie[/name_f] be too close for sisters? Which would you be more sad to lose? (Those kinds of questions)
Middle names flow really well when the emphasis is on not-the-first syllable. That’s why [name_f]Marie[/name_f], [name_f]Renée[/name_f], [name_f]Danielle[/name_f], and [name_f]Nicole[/name_f] were so popular as middle names.
[name_f]Celeste[/name_f]
[name_f]Solenne[/name_f]
[name_f]Felicity[/name_f]
[name_f]Lavinia[/name_f]
[name_f]Elizabeth[/name_f]
[name_f]Savannah[/name_f]
[name_f]Cascade[/name_f]