I had never thought of [name_f]Valley[/name_f] as an honour for [name_f]May[/name_f] birthdays / lily of the valley, but I love it! It seems like such a special name for you and your family. I like [name_f]Lilias[/name_f] for you, too - so lovely with El0wyn, although [name_f]Lily[/name_f] and [name_f]Wynnie[/name_f], too rhymey? And she is close to [name_f]Willa[/name_f], too - maybe she’s a middle?
I’m not a [name_m]Christian[/name_m] so [name_f]Hosanna[/name_f] feels like a lot to me, but I can really see that she suits your family, and I love your nickname ideas. I agree she might be best in the middle (forgive me if this is too gutter-minded but I worry that first syllable has the potential to be teased).
[name_f]Ruth[/name_f] is a lovely warm name, she feels a little traditional for your list but I must agree that [name_f]Ruthie[/name_f] and [name_f]Wynnie[/name_f] would be so adorable!!
I like [name_m]Kindred[/name_m]! Opposite of [name_f]Ruth[/name_f] in that she is wordier than some of your other choices, but I see the vision! Was your husband on board in theory but just didn’t like it for that specific baby? Maybe it wasn’t E’s vibe because it needed to be saved for her sister…?
[name_f]Rosemary[/name_f], [name_f]Merit[/name_f], and [name_f]Marigold[/name_f] are all great for this list - perhaps [name_f]Marigold[/name_f] especially since she feels a little more in the middle of the 2020s/vintagey [name_m]Venn[/name_m] diagram to me, like E - and I loooove [name_f]Goldie[/name_f]. [name_f]Rosemary[/name_f] is sweet, though, especially with your dream! [name_f]Merit[/name_f] feels more in line with [name_f]Valley[/name_f] and [name_m]Kindred[/name_m].
[name_f]Love[/name_f] the meaning of [name_f]Chavalah[/name_f], as neither [name_m]Christian[/name_m] nor Jewish I don’t really feel I can comment much on her other than that. I would assume a [name_f]Chavalah[/name_f] was Jewish but maybe that’s ignorance on my part?
[name_f]Fern[/name_f] is delightful and warm, she fits well with the vibes of [name_f]Ruth[/name_f], [name_f]Rosemary[/name_f], [name_f]Willa[/name_f], [name_f]Florence[/name_f]. I don’t think she’s too close to [name_f]Florence[/name_f] ‘Wren’, and love that she’s a longtime name crush. Sticking power is a good sign!
[name_f]Solveig[/name_f] is soooo cool and pretty, and I adore her with E!! What a stunning sisterset! [name_f]She[/name_f] fits less well with your other girls perhaps, so it depends how much you value cohesion between all their names.
My favourite combos you’ve mentioned ~
[name_f]Valley[/name_f] [name_f]Josephine[/name_f]
[name_f]Shiloh[/name_f] [name_f]Valley[/name_f]
[name_f]Ruth[/name_f] [name_f]Hosanna[/name_f]
[name_m]Kindred[/name_m] [name_f]Josephine[/name_f]
[name_f]Rosemary[/name_f] [name_f]Sonnet[/name_f] 
[name_f]Fern[/name_f] [name_f]Dorothy[/name_f]
[name_f]Sylvie[/name_f] [name_f]Fern[/name_f]
[name_f]Solveig[/name_f] [name_f]Beatrice[/name_f]
[name_f]Solveig[/name_f] [name_f]Meadow[/name_f]
I’m sure you’ve run all the possible combos in your mind, but other variations I like would be ~
[name_f]Solveig[/name_f] [name_f]Lilias[/name_f]
[name_f]Marigold[/name_f] [name_f]Ruth[/name_f]
[name_f]Fern[/name_f] [name_f]Solveig[/name_f]
[name_f]Sylvie[/name_f] [name_f]Josephine[/name_f]
[name_m]Kindred[/name_m] [name_f]Hosanna[/name_f]
[name_f]Sylvie[/name_f] [name_f]Hosanna[/name_f]
[name_f]Rosemary[/name_f] [name_m]Kindred[/name_m]
[name_f]Valley[/name_f] [name_f]Rosemary[/name_f]
[name_f]Dorothy[/name_f] [name_f]Meadow[/name_f]
[name_f]Ruth[/name_f] [name_m]Kindred[/name_m]
[name_f]Solveig[/name_f] [name_f]Marigold[/name_f]
[name_f]Solveig[/name_f] [name_f]Josephine[/name_f]
Sending you good wishes for that baby dust 
That is lovely 