I love all three of these as a potential sister one day to Rhett, but obviously can only use one of them.
Middles aren’t set in stone, but atm I’m liking short and sweet virtue names - Grace, Faith, Hope, Joy, etc.
Which one do you prefer as a sister to Rhett Mackenzie, and why? 
Thank you!
I voted [name_u]Skylar[/name_u] cause it feels a tad less trendy, but I love [name_u]Saylor[/name_u] too!
[name_u]Rhett[/name_u] & [name_u]Sawyer[/name_u] flow the best imo. I cannot wait until [name_u]Rhett[/name_u] arrives! 
Tricky one!
In terms of style, [name_u]Sawyer[/name_u] feels like the best fit with [name_u]Rhett[/name_u] — rugged yet tailored, smart and cool. But [name_u]Rhett[/name_u] and [name_u]Sawyer[/name_u] definitely sound like brothers to me!
[name_u]Skylar[/name_u] and [name_u]Saylor[/name_u] also fit nicely and are very cool and dynamic. [name_u]Saylor[/name_u] feels more 2022 and beyond, whereas [name_u]Skylar[/name_u] has a slight retro nostalgia feel which I particularly enjoy with [name_u]Rhett[/name_u].
I can see [name_u]Rhett[/name_u] and [name_u]Skylar[/name_u] as the heroes of a 90s coming-of-age movie, which is a big [name_u]Haley[/name_u] vibe 
I love the sound of [name_u]Rhett[/name_u] and [name_u]Skylar[/name_u] together! [name_u]Skylar[/name_u] is so sweet and energetic, and I love [name_u]Sky[/name_u] or [name_m]Ky[/name_m] as nicknames. And I’m totally getting ahead of myself here, but [name_u]Skylar[/name_u] [name_f]Joy[/name_f] would make a wonderful sister to [name_u]Rhett[/name_u] [name_u]Mackenzie[/name_u].
[name_u]Rhett[/name_u] and [name_u]Sawyer[/name_u] also work well but next to [name_u]Rhett[/name_u], [name_u]Sawyer[/name_u] sounds more like a brother to me than a sister.
[name_u]Saylor[/name_u] is gorgeous- such a wonderful name and [name_u]Rhett[/name_u] and [name_u]Saylor[/name_u] are so cute!! [name_u]Skylar[/name_u] is also fabulous
I’ve always been partial to [name_u]Skylar[/name_u] and love it with [name_u]Rhett[/name_u]! Seconding [name_u]Skylar[/name_u] [name_f]Joy[/name_f].
I voted [name_u]Skyler[/name_u] but my real favorite would be Shyler.
I have such a sweet spot for [name_u]Sawyer[/name_u] most of the time, but with [name_u]Rhett[/name_u]? Swoon.
[name_u]Sawyer[/name_u] [name_f]Grace[/name_f] is lovely.
^^ This is exactly what I was going to say.
As for Skylar vs Saylor…that’s a tough call. They both sound like your style, so I really think either one would work. 
Saylor is so you! I love it for your daughter! Saylor Grace, Saylor Hope, and Saylor Joy are stunning. I also love Sawyer but like @katinka said, I feel like it matches better as Rhett’s brother. Skylar is nms but Rhett and Skylar do sound nice.