I voted for [name_f]Eleanor[/name_f], [name_u]Everly[/name_u] and [name_u]Avery[/name_u], which I like with [name_f]Brynn[/name_f] in that order. I think names with strong “N” sounds sound slightly too repetitive for me with [name_f]Brynn[/name_f] (aside from [name_f]Eleanor[/name_f]), although that may be something you enjoy.
I love [name_u]Evelyn[/name_u] and [name_f]Elowen[/name_f] as middle name options. They flow nicely with [name_f]Brynn[/name_f].
[name_f]IMO[/name_f] I think [name_f]Elowen[/name_f] “fits” better with your other kids names though.