Oohh [name_u]Sunny[/name_u] is so cute! It’s the perfect ‘little sibling’ name too, but a name that I think could mature with a kid. Perhaps pair it with a ‘heavier’ more classic middle name to give it some gravitas.
I’d go [name_f]Sylvie[/name_f], [name_f]Luna[/name_f], [name_u]Sunny[/name_u] for you I think. But for me [name_f]Luna[/name_f]/Sunny are pretty interchangeable in terms of order. They’d all be lovely with your current children and are beautiful names.
In the last year I’ve had TWO cousins (on opposite sides of the family & who don’t know each other) name their daughters [name_u]Sunny[/name_u]. What’s even stranger is that they both have middles that begin with [name_u]Jo[/name_u].
100% [name_f]Sylvie[/name_f]! [name_u]Love[/name_u] your sibset.