Shaking up my lists a little bit and these six names are hovering on the boundary. Which would you add and which would you drop? (Big sibs are [name_f]Juno[/name_f] and [name_u]Kit[/name_u])
[name_u]Fife[/name_u]
[name_f]Frida[/name_f]
[name_f]Ianthe[/name_f]
[name_f]Manon[/name_f]
[name_f]Salome[/name_f]
[name_f]Tess[/name_f]
I would add…
[name_f]Tess[/name_f]
[name_f]Manon[/name_f]
[name_u]Fife[/name_u]
[name_u]Love[/name_u] those three with [name_f]Juno[/name_f] & [name_u]Kit[/name_u]!
I’d add [name_f]Tess[/name_f], [name_f]Ianthe[/name_f] & [name_f]Frida[/name_f] because they have the same spunky feel to me as the other sibs’ names do.
I like [name_f]Frida[/name_f]: nice association with [name_f]Frida[/name_f] [name_f]Kahlo[/name_f] and positive meaning (peaceful). [name_f]Frida[/name_f] does feel less youthful than [name_f]Juno[/name_f] and [name_u]Kit[/name_u], but it has the same offbeat, spunky quality to it. I also like [name_f]Tess[/name_f].
Keep [name_f]Ianthe[/name_f] and [name_f]Tess[/name_f]. Drop the rest.
[name_u]Fife[/name_u] - Dislike. It reminds me of a polluted and not all that intriguing city from my home area. What about [name_f]Ffion[/name_f]?
[name_f]Frida[/name_f] - [name_u]Love[/name_u]! I really dig its quirky retro vibe, and the name meaning. I toyed around with it for my list a while back, but couldn’t find the right combination for it, so it fell out of favor a little. I think it’d go great with your kids’ names.
[name_f]Ianthe[/name_f] - Like. Probably wouldn’t go for myself, but I think it’s pretty, and it’s not too hard to pronounce which is a plus.
[name_f]Manon[/name_f] - Like, but has potential for pronunciation issues. Also sometimes I can’t help but see it as “[name_m]Man[/name_m] on” which lessens my goodwill toward the name.
[name_f]Salome[/name_f] - Dislike. [name_m]Just[/name_m] not for me. Reminds me of Salame/Salami.
[name_f]Tess[/name_f] - I like it, and [name_f]Tessa[/name_f]. Find it much spunkier though than [name_f]Tessa[/name_f]. Can’t use personally due to an association, but I really dig the name.
I’d absolutely add [name_f]Tess[/name_f], it feels like a natural 3rd sibling name to [name_f]Juno[/name_f] & [name_u]Kit[/name_u].
Then I’d put [name_f]Frida[/name_f] & [name_f]Ianthe[/name_f] on the list for a more eclectic set.
[name_u]Fife[/name_u] I’d put on the middle name list, as a first name it’s a little too joke-y: “oh, and you are?” “I’m [name_u]Fife[/name_u]!” “Yeah, and I’m 8, so what’s your name?”; especially as she gets older.
[name_f]Manon[/name_f] is lovely in [name_m]French[/name_m] but I feel like people would try to pronounce it weirdly, in a faux [name_m]French[/name_m] way or it would become [name_f]May[/name_f]-non. MAH-nen or Muh-[name_f]NON[/name_f] could also be options but I personally don’t think either of them sound like [name_f]Juno[/name_f] & [name_u]Kit[/name_u]'s sister, it feels too complicated.
[name_f]Salome[/name_f] could work, but I like the quirk and simplicity of your set and [name_f]Salome[/name_f] doesn’t feel quirky nor simple to me.
I’d keep [name_f]Frida[/name_f], [name_f]Ianthe[/name_f] and [name_f]Tess[/name_f]. [name_f]Frida[/name_f] feels streamlined, unexpected but with history, and upbeat like [name_f]Juno[/name_f] and [name_u]Kit[/name_u]. I like [name_f]Ianthe[/name_f] but need to think about it with sib names - it has a softer feel. [name_f]Tess[/name_f] is great and goes well.
I like the sound of [name_u]Fife[/name_u] and want to include it but since someone said it’s not an appealing place I think it has to be crossed off. I think [name_f]Manon[/name_f] could be difficult outside [name_f]France[/name_f] as pp said, and [name_f]Salome[/name_f] just doesn’t feel streamlined enough (though you could argue [name_f]Ianthe[/name_f] doesn’t either I suppose though it does seem to fit better I think.) I think [name_f]Salome[/name_f] would also have pronunciation issues enough to be offputting.
I like [name_f]Tess[/name_f]! The other names have issues for me - either they sound unattractive, despite their positive associations, or they seem too convoluted next to your kids’ names. I would vote to add [name_m]Iggy[/name_m] (maybe [name_f]Inga[/name_f] nn [name_m]Iggy[/name_m]) and Revere. [name_m]Don[/name_m]'t know why exactly - they just sound quirky/streamlined/literary yet unexpected like your older kiddo’s names!
Thanks for all the opinions! [name_f]Salome[/name_f] and [name_f]Ianthe[/name_f] I do feel are a bit soft and long next to the other names, but then again maybe a more eclectic set is a good thing. I love [name_f]Manon[/name_f] said both the [name_m]French[/name_m] and Welsh way, but agree pronounciation is likely to be a real headache.
[name_f]Tess[/name_f] seems to be the winner here… I really like it and appreciate all its merits, but I’m not sure I love it (yet). [name_m]Will[/name_m] have to keep pondering that one. [name_u]Fife[/name_u] I do love but it feels more unknown (as a name) than the others and would be a bit more of an “out there” choice…
I’d add [name_u]Fife[/name_u], [name_f]Tess[/name_f] & [name_f]Frida[/name_f]
[name_u]Love[/name_u] love love [name_f]Frida[/name_f]! I’d love to meet a little girl with this name. I also want to like [name_f]Salome[/name_f] but my husband has ruined it for me by saying it reminds him of salami. 
I’d add [name_f]Ianthe[/name_f] and [name_f]Tess[/name_f]. 
Both seem really you! [name_f]Manon[/name_f] and [name_f]Salome[/name_f] are lovely, but they seem more like MNs for you? Maybe I’m off my rocker, but that’s the impression I’ve gotten. (I think [name_f]Ianthe[/name_f] [name_f]Manon[/name_f] and [name_f]Tess[/name_f] [name_f]Salome[/name_f] would be lovely!)
I’ve got [name_m]Eoghan[/name_m] [name_m]Daniel[/name_m] [name_u]Fife[/name_u] on my own list, so, though [name_u]Fifer[/name_u] feels like a girls’ name to me, [name_u]Fife[/name_u] feels all boy? I guess it wouldn’t have to be, but I find it hard to see it on a girl. [name_u]Fife[/name_u] could be really sweet, but it almost seems more like a MN, regardless? I’m not really brave enough to use it up front, though I love it. I actually really love [name_f]Ianthe[/name_f] [name_u]Fife[/name_u] or [name_u]Fife[/name_u] [name_f]Ianthe[/name_f] for you!
Ooh lovely suggestions, thank you! I totally agree that [name_f]Salome[/name_f] seems more like a middle name for us… but I was thinking that I could possibly use [name_m]Sol[/name_m] (already on my list) as a nn and get two for the price of one, so to speak! The salami thing is valid and really puts me off though, as does the macabre story of [name_f]Salome[/name_f] in the Bible. I think I’ll continue to just admire this one from afar…
After some more thinking I feel [name_f]Ianthe[/name_f] is perfect - it has the intriguing, spunky yet understated feel of the sibs. I like that it has a different syllable number so seems to hold its own in the group. [name_f]Tess[/name_f] I love but now feel that starting with a T after [name_u]Kit[/name_u] ending in a t is just not ideal (also another one syllable). [name_f]Frida[/name_f] doesn’t feel right after more thought. [name_f]Manon[/name_f] however is growing on me and works well with the sibs so I would add it back in!
[name_u]Fife[/name_u]: I’m neutral about the sound of it. Associations? [name_u]Fife[/name_u] reminds all the time of [name_f]Michelle[/name_f] [name_m]Pfeiffer[/name_m] - which is bad, not because of her, but because she is all I can think about when I hear [name_u]Fife[/name_u]
[name_f]Frida[/name_f]: I [name_u]LOVE[/name_u] this one - [name_f]Kahlo[/name_f] is a cool connection and it means “peace”! It’s a bit old ladyish, but it sounds so strong…
[name_f]Ianthe[/name_f]: there are 2 main pronunciations of this name, one the I has an “EE” sound and the other the I has an “EYE” sound. My favorite is first prn, again it sounds very strong. “[name_f]Violet[/name_f] flower” is a pretty meaning.
[name_f]Manon[/name_f]: [name_f]Maria[/name_f] variants and diminutives are my thing! I prefer the [name_m]French[/name_m] prn over the Dutch one. Sincerely, to my eyes and ears this name is beautiful, but maybe too much with a sister Jun0 (excess of Os - mainly the Dutch prn.)?
[name_f]Salome[/name_f]: it used to be a favorite, until I found out that everyone pronounces this name differently. I am partial to the Portuguese Salomé (Portuguese is afterall my first language); [name_f]Salome[/name_f] in English DOES sound like salami. The meaning “peace” is nice, but salami?! [name_m]Just[/name_m] [name_m]Sol[/name_m] is MUCH prettier ([name_f]Salome[/name_f] is more trouble than it’s worth).
[name_f]Tess[/name_f]: only my favorites on this list? 
[name_f]Tess[/name_f] is pretty, short and with no pronunciation problems (win!). “The meaning is uncertain, but it could be derived from Greek θε”ος (theros) “summer”, from Greek θε”ιζω (therizo) “to harvest”, or from the name of the Greek island of Therasia (the western island of Santorini)” - Behind the Name site. Not bad, I like it - my #1 for you from this list. [name_f]Tess[/name_f] is so short that a long middle ([name_f]Tess[/name_f] [name_f]Endellion[/name_f]) or even 2 middle names (whispering use [name_u]Hero[/name_u]) are preferable.
Added: [name_f]Tess[/name_f], [name_f]Frida[/name_f] and [name_f]Ianthe[/name_f] (I have doubts about the last one).
Dropped: [name_f]Salome[/name_f], [name_f]Manon[/name_f] and [name_u]Fife[/name_u].