neither is particularly kind. but I say Mulan. pocahontas' actions got kocoum killed and she didn't really seem to care save for like 2 minutes. she's a bit self involved.

Mulan was kind enough to give a toy back to a child being bullied. I can't think of Pocahontas doing anything that I would describe as kind.

^
Pocahontas isn't unkind, she just doesn't really go out of her way to show kindness like that, or telling Shang she thinks he's a great Captain or make a bad joke to try to cheer him up.