If not [name_f]Delilah[/name_f] (which I think would go wonderfully with your other two) about [name_f]Lorelei[/name_f] or [name_f]Liliana[/name_f] nn [name_f]Lila[/name_f]?
But I think [name_f]Lilah[/name_f] works, and it’s more importers you like the single name than it’s the so called perfect sibset!