[name_f][/name_f]From yours, I'd consider:
[name_f][/name_f][name_f]Alma[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_m]Amaris[/name_m] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Charis[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Isola[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Haven[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Keziah[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Lenora[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Saskia[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Story[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Tallulah[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Vada[/name_f] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Sylvie[/name_f] [name_m]River[/name_m]
[name_f][/name_f][name_f]Nolia[/name_f] [name_m]River[/name_m]
[name_f][/name_f][name_f]Luthien[/name_f] [name_m]River[/name_m]
[name_f][/name_f][name_f]Ardith[/name_f] [name_m]River[/name_m]
[name_f][/name_f][name_m]Athaliah[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_f]Talitha[/name_f] [name_m]River[/name_m]
[name_f][/name_f][name_f]Zelie[/name_f] [name_m]River[/name_m]
[name_m]Ambrose[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Amias[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Boone[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Caspian[/name_m] [name_f]Willow[/name_f]
[name_f][/name_f][name_f]Credence[/name_f] [name_m]River[/name_m]
[name_f][/name_f][name_m]Elam[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Elwood[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Evander[/name_m] [name_f]Willow[/name_f]
[name_f][/name_f][name_m]Lennox[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Oren[/name_m] [name_f]Willow[/name_f]
[name_f][/name_f][name_m]Ozias[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Harland[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Taliesin[/name_m] [name_f]Willow[/name_f]
[name_f][/name_f][name_m]Zephan[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Sylvan[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Tobin[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Solomon[/name_m] [name_m]River[/name_m]
[name_f][/name_f][name_m]Other[/name_m] ways I'd ponder:
[name_f][/name_f]As less direct options, I love the idea of [name_f]Wildrose[/name_f] as a middle [name_f][/name_f]- [name_m]Wil[/name_m] from Wi11a, R_s from R1vers, and a nature-y option.
[name_f][/name_f]I like [name_m]Rowan[/name_m] for similar reasons [name_f][/name_f]- R from R1vers, a tree name for W1llow, nature-y for both.
[name_f][/name_f]Everwild could work too, in a similar way!
[name_f][/name_f]I’d also ponder on [name_m]Wildoak[/name_m], [name_m]Woodrow[/name_m], [name_m]Oakland[/name_m], [name_m]Oren[/name_m], [name_m]Forest[/name_m], and [name_m]Alder[/name_m] too [name_f][/name_f]- woodsy, naturey names
[name_f][/name_f]