A prettier version of Ariel but they look pretty much alike. Just give them the same hair and lips and they'd be the same.

Just a little bit. I think Ariel is slightly prettier, though.

A very tiny bit. Giselle is prettier though.

^

At first I thought "No" but looking at the pictures they have some similarities. Giselle has a thinner and longer face though.

In the face.

Most of the Disney characters're a copy of very popular ones. Disney it self made a video before The Princess and The Frog was premier and posted it on the Disney site admitting that they used Jasmine,Ariel and Belle to create Tiana.

Not really....A little bit, but I see differences in their eyes, noses, lips, smiles, face shape, bodies....And coloring of course.

I don't see it..

Considering her entire character was a spoof on most princesses up to that point, with traits of many princesses combined into one character, I doubt it's a coincidence.