They have a cohesive feel!
I would go [name_f]Nicolette[/name_f] nn [name_f]Nikki[/name_f] & [name_f]Daniella[/name_f], nn [name_f]Danni[/name_f], if want to lean into the spunky 80s genre or at least [name_f]Nicki[/name_f] & [name_f]Dami[/name_f] (Damiana).
Meanwhile, [name_m]Cole[/name_m] & [name_f]Dami[/name_f] as a pair evokes 90s high school grunge to me.
[name_f]Nicolette[/name_f] and [name_f]Damiana[/name_f] also give a European, slightly witchy vibe so you could also mix up the nicknames - [name_f]Nixie[/name_f] & [name_f]Dama[/name_f] or [name_m]Nico[/name_m] & [name_f]Mia[/name_f].
Anyway, depends what style and imagery you’re going for! Would think about [name_f]Dami[/name_f] over [name_f]Dani[/name_f], as more intuitive for [name_f]Damiana[/name_f] but of course [name_f]Dani[/name_f] works too.