Your two have lovely names 
I really like [name_f]Paulina[/name_f] [name_f]Grace[/name_f] nn ‘Polly’ from your options! It’s elegant and solid, but with a sort of daintiness to it too!
[name_f][/name_f][name_f]Rosalia[/name_f] [name_f]Grace[/name_f] is a close second [name_f][/name_f]- it’s feels arty, melodic and summery.
[name_f][/name_f][name_f]Dalia[/name_f] [name_f]Grace[/name_f] is nice too [name_f][/name_f]- floral without frills. I think you could use it as a [name_f]Dolly[/name_f] [name_m]Parton[/name_m] fan. You wouldn’t be using the exact name and nicknames [name_f]Lia[/name_f] or [name_f]Dia[/name_f] could be used instead if you were worried? Still, your other options are great so if you’re not comfortable with this one, I’d go with one of the above.
[name_f][/name_f][name_f][/name_f]
A couple of suggestions:
[name_f][/name_f][name_f]Liv[/name_f] → as a middle name? A nod to [name_f]Olivia[/name_f] with a lively meaning, a bit like [name_f]Joy[/name_f]?
[name_f][/name_f][name_f]Delfina[/name_f] [name_f]Grace[/name_f] (Delfi, [name_f]Della[/name_f], Deenie)
[name_f][/name_f][name_f]Constanza[/name_f] [name_f]Liv[/name_f] / [name_f]Constanza[/name_f] [name_f]Grace[/name_f] (Connie, [name_f]Tanzy[/name_f], Cozy)
[name_f][/name_f][name_f]Luciana[/name_f] [name_f]Grace[/name_f] (Lucy, [name_f]Lula[/name_f], [name_f]Luna[/name_f], Lula)
[name_f][/name_f][name_f]Samara[/name_f] [name_f]Liv[/name_f] / [name_f]Samara[/name_f] [name_f]Grace[/name_f] (Mara, [name_f]Sara[/name_f], Ari)
[name_f][/name_f][name_f]Leandra[/name_f] [name_f]Grace[/name_f] (Lea, [name_f]Lannie[/name_f], Leni)
[name_f][/name_f][name_f]Noemi[/name_f] [name_f]Olivia[/name_f] / [name_f]Noemi[/name_f] [name_f]Liv[/name_f] / [name_f]Noemi[/name_f] [name_f]Grace[/name_f] (Emi, Noa)
[name_f][/name_f][name_f]Isidora[/name_f] [name_f]Grace[/name_f] / [name_f]Isidora[/name_f] [name_f]Liv[/name_f] (Isa, [name_m]Izzy[/name_m], [name_f]Dora[/name_f], [name_f]Dorie[/name_f], Dodie)