I guess...she would love Jasmine's sassy and outspoken personality.

Or Pocahontas.

And Pocahontas and maybe Jasmine

by far
or Jasmine, Belle or Pocahontas

Definitely. They have so much in common. Her second and third would be Ariel and Jasmine, respectively.

Mulan would be her favourite, and she would also like Ariel and Jasmine, possibly Pocahontas too. I don't think she would care about any of the others.

Mulan is a warrior so I think Merida would love her

I'm in the vast minority, but I think Merida would relate to Rapunzel since she feels kind of trapped by her mom, like her mom knows best, but Rapunzel actually realized that her mom wasn't always looking out for her, so I feel like Merida would like that, and Rapunzel does wield a weapon as well as go around being a wild child and getting messy. Even with her pink and purple dress I assume Merida would still like all the stuff Rapunzel does.
I guess Mulan is the obvious option though (rebel against society and a warrior princess without a definitive love interest, I don't know why I didn't choose her option.

^I agree with you, I think Mulan is the obvious choice but not necessarily the right one, because Mulan seems more "adult" than Merida and Rapunzel she can maybe relate to on maturity.

and Mulan and Jas