I’ve been thinking about the following sibsets recently. I’d love your opinions, suggestions, etc. Do you think they fit? Do you have any ideas for additional siblings?
Elsinore nn Nora, Lilivere nn Vera, Madelief nn Maddie, Vivendel nn Vivi
Paloma nn Lola, Catalina nn Tali
Elsinore nn Nora, Lilivere nn Vera, Madelief nn Maddie, Vivendel nn Vivi → I think this is a really well-matched set! I like the longer, fantasy-esque full names with the more familiar nicknames. I would name another sibling Roselaine ‘Rosie’ or ‘Lainey’, [name_f]Clarimond[/name_f] ‘Claire’, or [name_f]Melusine[/name_f] ‘Lulu’ or ‘Lucy’.
Paloma nn Lola, Catalina nn Tali → Also a nice set! I think the first names pair really well together and the nicknames are great too. I do find saying “Lola and Tali” to be a bit of a tongue-twister myself, maybe because of all the L sounds, but stylistically I like them together. I would name another sibling [name_f]Mirabel[/name_f] ‘Mira’ or ‘Miri’, [name_f]Alma[/name_f], [name_f]Valentina[/name_f] ‘Leni’ or ‘Nina’, or [name_f]Sofia[/name_f] ‘Sofi’.
[name_f]Elsinore[/name_f], [name_f]Lilivere[/name_f], [name_f]Madelief[/name_f] and [name_m]Vivendel[/name_m] are lovely - mystical and magical and powerful but with grounded, familiar nicknames! They work well!
Additional siblings: [name_f]Elsinore[/name_f], [name_f]Lilivere[/name_f], [name_f]Madelief[/name_f], [name_m]Vivendel[/name_m] and…
[name_f]Morrigan[/name_f] nn [name_f]Annie[/name_f], [name_f]Minnie[/name_f], or [name_f]Maggie[/name_f]
[name_f]Angharad[/name_f] nn [name_f]Annie[/name_f], [name_f]Anna[/name_f], [name_f]Aggie[/name_f], or [name_f]Addy[/name_f]
[name_f]Amaryllis[/name_f] nn [name_f]Millie[/name_f], [name_f]Mary[/name_f], [name_f]Amy[/name_f] or [name_f]Issy[/name_f]
Carisbrooke nn [name_f]Cassie[/name_f], [name_f]Caris[/name_f], [name_f]Brooke[/name_f] OR [name_f]Crissie[/name_f]
[name_f]Gwyneira[/name_f] nn [name_f]Gwen[/name_f], [name_f]Winnie[/name_f] or [name_f]Eira[/name_f]
[name_m]Taliesin[/name_m] nn [name_m]Taz[/name_m], [name_m]Tal[/name_m], [name_m]Lee[/name_m]
[name_m]Galahad[/name_m] nn [name_f]Addy[/name_f], Ads, or [name_m]Hal[/name_m]
[name_m]Caedmon[/name_m] nn [name_m]Cade[/name_m]
[name_m]Brynmor[/name_m] nn [name_m]Rory[/name_m], Bry, [name_f]Bryn[/name_f]
[name_m]Astraeus[/name_m] nn [name_m]Asa[/name_m]
[name_f]Paloma[/name_f] and [name_f]Catalina[/name_f] have international flair, with both sophistication and liveliness. [name_f]Lola[/name_f] and [name_f]Tali[/name_f] are lovely too 
More sibling ideas:
[name_f]Paloma[/name_f], [name_f]Catalina[/name_f] and…
[name_f]Adaluna[/name_f] nn [name_f]Lulu[/name_f]
[name_f]Rosalba[/name_f] nn [name_f]Rosie[/name_f]
[name_f]Marisol[/name_f] nn [name_m]Sol[/name_m] or [name_f]Millie[/name_f]
[name_f]Noemi[/name_f] nn [name_f]Emi[/name_f]
[name_f]Antonella[/name_f] nn [name_f]Nell[/name_f]
[name_f]Miranda[/name_f] nn [name_f]Mira[/name_f], [name_f]Miri[/name_f], [name_f]Mindy[/name_f]