On your list, I'd use:
LucyJuliet (that spelling; mn only)
AliceBeatrice (my daughter's fn)
EmilyClare; perhaps
Clara
I'd avoid:
LunaScarlettWillaRubyIvyGemmaOlive (but I'd consider
Olivia)
Georgia (but I'd use
Georgina)
AmeliaPoppyClio (
Cleo) (but I like
Chloe and
Clodagh)
We used
Beatrice (a family name) as the mn for our first daughter. When she died and I had another daughter, we wanted to have a link between them and used
Beatrice as the new baby's fn. She is very happy that we did. Might you consider actually using
Stella, perhaps as a mn?
Seren is all right, but if you're not Welsh it's a bit of a stretch.