I definitely prefer Nova. Carolina is also a fine name.
From your list I like Hadley and Carolina. Carolina has other nn besides Carol. My favorite nn for it would be Lena.
I think Hadley would be my favorite.
Hadley Grace or Hadley Madelynn sound great!
Larken is cute as well! Looks like most all of ya'll like Carolina so far! :)
I also like Carolina the most. Linny as a nn, perhaps?
Nova Leigh Harmon is lovely (I think separating Novaleigh into a double fn is better).
Nova Lynn Harmon if you want to use Lynn
Hadley Harmon- I love alliterative names, although it is androgynous
Mason is better than Macyn
Not fond of Carolina since you live in SC
Also wanted to add that Novalie is another spelling of this name, used in Sweden.
that is a pretty spelling also!
I love Madelynn Grace - Also on my list but with a different middle name.
I also like Novaleigh as it's kinda quirky and different
I think Madelyn wins by far! Honestly, I really don't care for any of the other names. I would spell it Madeline though.
I like Nova and Madelynn :)