Well if I was to see/hear/meet an
Isabella,
Annabella or
Arabella I know my first thought would be "what a lovely name for a little girl", because thay are all simply beautiful names, and are elegant, refind, and regal!
I personaly like
Arabella a little bit more because it is less popular and also because of it's Scottish connections. And I deffinately don't think "Arab named
Ella", to me it's clearly defined that the name is Ara +
Bella! It has rather the thought of beautiful music because of Ara sounding like
Aria and
Bella like Ballet or a southern belle and meaning beautiful.
Annabella is a bit long and that's why I like the spelling Anabella a bit better. But either way it's really a classic name that to me isn't used quite enough.
Isabella is also beautiful but is probably my least favorite of the three because of it's recent popularity surge.
I think either one would be perfect on any little girl and have several nickname possibilities in case the whole name is too long or not suit.
Hope this helps!
Laurie :)