[name_m]Hi[/name_m] there.
[name_f]Leah[/name_f] & [name_m]Wesley[/name_m] are lovely!
Here are my thoughts on your list:
[name_f]Olivia[/name_f] [name_u]Kenzie[/name_u] Cahill-I love [name_f]Olivia[/name_f]. It goes really well w/[name_f]Leah[/name_f] & [name_m]Wesley[/name_m]. And the nn [name_f]Livy[/name_f] is so so sweet. [name_f]Olivia[/name_f] is super duper popular though, if that’s a concern for you. [name_u]Kenzie[/name_u] is kind of lacking substance to me. Especially w/such a classic like [name_f]Olivia[/name_f].
[name_u]Aubrey[/name_u] [name_f]Olivia[/name_f] Cahill-I don’t like [name_u]Aubrey[/name_u] for some reason, yet adore [name_f]Audrey[/name_f]. [name_f]Audrey[/name_f] just has that classic [name_f]Audrey[/name_f] Hepburn association. [name_u]Aubrey[/name_u] just seems trendier.
[name_f]Myla[/name_f] [name_f]Aubree[/name_f] Cahill-This spelling seems a little tricky, because is it Mee-luh or [name_f]My[/name_f]-luh? I think that Mee-luh spelled [name_f]Mila[/name_f] is gorgeous. The ‘y’ isn’t as simple & elegant looking. Either way, I think that this may be a tad close to [name_f]Leah[/name_f]. And also very popular.
[name_f]Kendra[/name_f] [name_u]Aubrey[/name_u] Cahill-Hm. This is different. I don’t love it personally, but it’s not awful & fits in well.
[name_u]Aubrey[/name_u] [name_u]Mackenzie[/name_u] Cahill-[name_u]Aubrey[/name_u] [name_f]Olivia[/name_f] flows way better.
[name_f]Olivia[/name_f] [name_u]Mackenzie[/name_u] Cahill-Hm. I like this slightly more than [name_f]Olivia[/name_f] [name_u]Kenzie[/name_u].
[name_f]Olivia[/name_f] [name_f]Kenzley[/name_f] Cahill-[name_f]Kenzley[/name_f] just looks off.
[name_f]Olivia[/name_f] [name_u]Aubrey[/name_u] Cahill-This is my favorite [name_f]Olivia[/name_f] combo of what you’ve got. Although I’d love [name_f]Olivia[/name_f] [name_f]Audrey[/name_f]. 
[name_u]Madison[/name_u] [name_f]Kenzi[/name_f] Cahill-[name_u]Madison[/name_u] is okay. It’s just been so trendy over the years, & I just don’t care for ‘son’ names for a girl.
[name_u]Madison[/name_u] [name_u]Aubrey[/name_u] Cahill-This flows better.
[name_f]Kendra[/name_f] [name_u]Madison[/name_u] Cahill-Hm. Either [name_f]Kendra[/name_f] [name_u]Aubrey[/name_u] or [name_f]Kendra[/name_f] [name_u]Madison[/name_u] sound okay.
[name_u]Madison[/name_u] [name_f]Kenzley[/name_f] Cahill-[name_u]Madison[/name_u] [name_u]Aubrey[/name_u] is better.
A few girl suggestions:
[name_f]Abigail[/name_f]
[name_f]Claire[/name_f]
[name_f]Gemma[/name_f]
[name_u]Holly[/name_u]
[name_f]Ivy[/name_f]
[name_f]Lydia[/name_f]
[name_f]Margot[/name_f]
[name_f]Maren[/name_f]
[name_f]Nora[/name_f]
[name_f]Phoebe[/name_f]
[name_f]Sofie[/name_f]
Boy names
[name_m]Colton[/name_m] (cousin names [name_m]Cole[/name_m]
If it’s too close)-If you’re close to [name_m]Cole[/name_m] & see him often, it may be too close.
[name_m]Gunnar[/name_m]-I just don’t love this. It’s just the nn ‘[name_m]Gun[/name_m]’ is kind of off.
[name_u]Everett[/name_u]-This is handsome, & I think fits in well w/your crew. A bit popular, but not super over done.
[name_u]Jonah[/name_u]-love love love-Ooh, me too! Very handsome. Boyish yet gentle & classic.
[name_u]Micah[/name_u]-This is fine too. Similar style as [name_u]Jonah[/name_u], but I love [name_u]Jonah[/name_u] way more for some reason.
[name_u]Jameson[/name_u]-This is quite nice. And I like this spelling. The nns [name_u]Jem[/name_u] & Jass are really cute too.
[name_u]Ryder[/name_u]-I must have an aversion to 'y’s, because I really prefer [name_m]Rider[/name_m]. And it just seems easier, since that’s how the word is spelled. [name_m]Rider[/name_m] is really cool. Simple & not too popular.
[name_m]Rhett[/name_m]-Kind of cool. Not my personal favorite, because it seems a little abrupt. I think that [name_u]Everett[/name_u] is softer.
[name_u]Jackson[/name_u]-This is fine. It fits well w/your crew, but it’s just sooo over done.
[name_u]Dakota[/name_u]-Ooh, fun. I rarely see this on lists. I think that it’s a totally different style from [name_f]Leah[/name_f] & [name_m]Wesley[/name_m], but I personally really like it. It’s very nature-y & artsy sounding. And the nn [name_m]Kota[/name_m] is just sweet.
[name_u]Evan[/name_u]-This fits in great w/[name_f]Leah[/name_f] & [name_m]Wesley[/name_m]. Not sure why I can’t personally get into it, but it’s a good name.
[name_u]Hudson[/name_u]-I feel like half the little boys I meet are called this. It’s just getting kind of old. It’s not a bad name though, & fits in well.
[name_m]Liam[/name_m]-I love this, but it’s sooooo popular & also too close to [name_f]Leah[/name_f].
[name_m]Callum[/name_m]-Ooh, love [name_m]Callum[/name_m]! Great alternative to [name_m]Liam[/name_m]. It has a similar feel w/the very cool sporty nn of [name_u]Cal[/name_u].
[name_u]Jonah[/name_u] [name_u]Owen[/name_u]-Hm. I adore [name_u]Owen[/name_u] in general, but don’t care much for this flow. I like [name_u]Jonah[/name_u] [name_u]Everett[/name_u] or [name_u]Jonah[/name_u] [name_m]Rider[/name_m].
[name_u]Jackson[/name_u] [name_u]Owen[/name_u]-I don’t like the flow of this, because they both end in ‘n’. [name_u]Jackson[/name_u] [name_u]Everett[/name_u] or [name_u]Jackson[/name_u] [name_m]Rider[/name_m] are good.
[name_u]Jackson[/name_u] [name_u]Everett[/name_u]-Oh yeah, that’s better!
[name_u]Rowen[/name_u] [name_m]Oliver[/name_m]-I love [name_u]Rowan[/name_u] spelled that way, because that’s how the tree is spelled. Such a beautiful name & it goes nicely w/[name_f]Leah[/name_f] & [name_m]Wesley[/name_m]. [name_u]Rowan[/name_u] [name_m]Oliver[/name_m] is sweet.
A few boy suggestions:
[name_m]Beckett[/name_m]
[name_u]Bennett[/name_u]
[name_m]Clark[/name_m]
[name_m]Conor[/name_m]
[name_u]Dylan[/name_u]
[name_u]Emmett[/name_u]
[name_m]Gabriel[/name_m]
[name_u]Grady[/name_u]
[name_m]Holden[/name_m]
[name_u]Jude[/name_u]
[name_m]Jonas[/name_m]
[name_m]Milo[/name_m]
[name_m]Oscar[/name_m]
[name_m]Odin[/name_m]
[name_u]River[/name_u]
[name_u]Tristan[/name_u]
[name_f]Hope[/name_f] this helps. 