Well, I agree that it's very feminine. It's a tad bit flouncy, however. Plus, if you call her Arabella Noelle, it's a little too much -ell sound in a name, in my opinion. Belle and Bella are nice, not just as nicknames, either.
Isabella is a little trendy, but then there's the namesake Isabella Rossellini, which is great. I hope I spelled that right.
I would pick either Arabella or Noelle and find a different fn/mn for it depending on what you pick.