I love
Lyra.
Lily and
Lyra as a sibset is just too much, too flowery and similar. I think if you want to use
Elsa with another middle name for
Lily you need something one syllable.
Lily Elsa MaeLily Elsa Sloane Lily Elsa KayLily Elsa RaeLily Elsa LynnLily Elsa Blaire
Lily Elsa Ash