I think [name_f]Brielle[/name_f] is your winner! It has a distinct sound from [name_m]Jacob[/name_m], [name_u]Noah[/name_u], and [name_f]Avah[/name_f], while still being familiar and fitting in with her siblings’ widely-used names.
Out of those I think Reyna goes perfectly with the other siblings! If you want an -ay pronunciation I would personally go Aneia for the spelling since all the others on the list I would pronounce with a -nye sound. Also would suggest Anya for for you since it has the Y like the other names but feels more classic like Reyna or Brielle! Also Aria/Arya would work really well, and by extension Arianna
I like [name_f]Anaiah[/name_f] and [name_f]Reyna[/name_f] best with your set! I think I forgot to suggest [name_f]Anais[/name_f] but that would be pretty too I think.
Of that list I vote [name_f]Brielle[/name_f] followed by [name_f]Reyna[/name_f]. They are distinct from the sibset but fit right in and I think would be pronounced the way you prefer.
Names are hard! We feel pressure to get it right and I think it gets harder as the sibset grows. Good luck!