It depends on what exactly the last name is but I can see [name_f]Calla[/name_f] clashing a bit.
[name_f]Sylvie[/name_f] is a lovely name. [name_f]Pretty[/name_f] and strong with some nice imagery and associations. I’m not as much a fan of [name_f]Dahlia[/name_f] or [name_f]Dove[/name_f].
For boys, [name_m]Rowan[/name_m] is my favorite. It’s light, cool but substantial.