i think Pocahontas

I can see Mulan finding this funny and kickass.

It's hard to choose Pocahontas as being any of the princess' favorite movie, because she didn't get to stay with John. But, the movie relates, quite strongly, the value of duty to one's people and nation and I think Mulan could relate and even appreciate that kind of dedication.

Also, I agree with becca85, because Mulan didn't find romance important, and Pocahontas didn't end up with John. Also, Mulan is struggling to find who she is, and Pocahontas is a strong female character who is also struggling to find where she fits, and Mulan would relate to that.

I agree with becca85.

Pocahontas, Aladdin or Princess and the frog. Maybe I'm seeing this too much from my own perspective but I imagine her liking Pocahontas a similar way to me, liking the character more than the actual movie. I think she'd relate to Pocahontas' journey, and fun side, strength and sense of duty, but as for the movie I think it's a bit too serious to be her favourite, she's a bit goofy and funny. Plus even though Pocahontas doesn't leave with John their romance is still the focal point of the movie, so I'm not sure how much Mulan would be into that.
Aladdin is funny and has some action too. I picked princess and the frog because it's funny, sweet and I think she'd relate to Tiana, hard working, having to prove herself, people not thinking she's capable because of who she is, more than she could relate to Jasmine :)

or maybe Pocahontas, because of the action.