I prefer [name_f]Elisabeth[/name_f] to [name_f]Caroline[/name_f] but I do like [name_f]Carys[/name_f] a lot and I don’t like [name_f]Lisi[/name_f] (too hissy and soft for me).
I like [name_f]Sisi[/name_f] though & you could also use [name_f]Lily[/name_f] for [name_f]Elisabeth[/name_f] (and all the other options, [name_f]Elsie[/name_f], [name_f]Bess[/name_f] etc).
So overall, prefer [name_f]Elisabeth[/name_f] but if choosing on nicknames, very drawn to [name_f]Carys[/name_f] (I’d personally pick [name_f]Carys[/name_f] as a standalone over [name_f]Caroline[/name_f], it also precludes [name_f]Carrie[/name_f] which I’d not keen on).