Most citrus is defined as sour, though Delienne is friendly. [personality ref]
This is a good clue. It was probably the most solid that I had to go one when I was reading.
So get away from me
Fluff
This arcade fire album ain't for you,
Funeral; Delienne has witnessed a lot of death in her lifetime, though she hasn't died yet [history ref]
Probably the most usable of their album titles was "neighborhood" and "funeral", so I'd pass this clue. Delinne's mother did die after birth, so even if there is not "a lot" of death, there is still enough to make this work.
Sorry to burst your bubble,
But you can do that on your own,
She has a horn, so she can burst her own bubble [unicorn ref]
Great species ref. x3
Coal.
Delienne is black, like coal [color ref]
Good color ref.
Pass, with flying colors.