Ariel would be VERY UNCOMFORTABLE with what Merida did.

Tiana, Belle, Aurora, Mulan.

Mulan tiana aurora and maybe Pocahontas and belle

Mulan, Belle, and maybe Aurora. But especially her since she cares with her parents so much and she was willing to do anything to keep them safe.

Mulan or Belle. But Mulan would not be above rebelling
against a parent

Especially since she was also poisoned with something she thought was a gesture of kindness as well. But I imagine all of them being uncomfortable with it.

@AnimaIuco, neither would Belle. Belle and Maurice have such peaceful relationship because Maurice has quite liberal parenting style. Belle herself can be stubborn and disobedient.

All of them, but in particular Tiana, Snow White, Belle, and Mulan.

Tiana: Not only is she extremely family oriented (her entire dream is a tribute to her deceased father), but she also wants to use food as a means to make people happy and bring them together. She would be repulsed and horrified by the idea of using food to curse someone, particularly a family member.

Snow White: She herself was cursed by poisoned food, and on top of that she has much more in common with Elinor than Merida. She would absolutely side with Elinor in this situation, and see Merida as someone akin to the Evil Queen.

Belle and Mulan: Both are very family oriented people, and are willing to sacrifice nearly anything for their families. They would be shocked and disgusted by Merida's actions, and would be unable to understand her decision making process behind it.