I know an Ariel, who has the same shape of gorgeous hair, but it's black. We loved it. Obviously she was not named for the movie but she said it was annoying growing up. But after I met her and got past her pretty hair, the thought of the TLM never crossed my mind. I think it would be ironic if she ended up with red hair but I don't think I would let it deter me. I too would spell it Ariel, but regardless I like it.
I wouldn't use it since she will have red hair. My DH is a redhead (and my mom, uncle, aunt and grandpa are too) so we know the chances of us having a redhead is very high so I crossed off Annie from our list.
I think it's nice, although I prefer the spelling Ariel. I would actually pronounce Arielle a little differently, putting the stress on the end (air-ee-ELL) vs (AIR-ee-ell).
I think of Arielle as Are-ee-el for some reason. If you're going for Ariel like the mermaid, I'd spell it that way. I can move past the movie association and find it an ok name... I wouldn't let it deter you.
Re: Girls name
Married my best friend 10/12/12
TTC 1 since 10/12
NTNP Fall 2013 to focus on a healthier lifestyle