@chrltt-t Hey Chrltt-t hope your doing well, I just want to let you know that I am fan of your Amberstone Trilogy, for it is well written and thought out. I would like to offer a few recommendations or suggestions, that could help with your story. In the Amberstone Trilogy one twin is born blessed while the other twin is born cursed with ill-fate.
I was thinking for the twin that was born cursed with ill-fate, maybe instead of being born with a red tear dropped shaped birth mark, she could be born with one brown eye and one gold eye. Some other things could be, is that she is also born with albino skin and has leukemia or anemia. For these conditions show that she is ill and not normal.
Also I was thinking a nickname for Elianna could be ‘Flower’ since Nadia likes Lilacs a type of flower.
These are just some ideas or thoughts that I am pitching out, which I think could help with your story.