Avery is too popular. My niece is 9 and it wasn't too common then, but I think it's more so now. Check your names against a popularity list like this:
I didn't check Coraline, but I kinda like it and haven't heard commonly. How is it pronounced though? Could also consider Coralynne or Coralynn if it is to be pronounces that way.
Kaylnn is just a different spelling variation of something that feels too common to me. And it seems to be missing a vowel after the "L" IMO.
Good luck! I have less ideas than you, and I am nearly 23 weeks!