What would the relationships between the princesses be: Cinderella and Merida?

That's interesting...I think it's the same as Elinor and Merida's relationship

Cinderella- *working*
Merida- Let's get out of here >3> too dull and boring
Cinderella- O....O no
Merida- Pfffft, once boring always boring. Peace

Merida would be bored with Cinderella and think she's spineless for never standing up to her stepfamily. she wouldn't like how traditionally feminine or responsible she is.

Cinderella would find Merida an immature brat and would probably love to see her try that with her stepfamily and see how long it lasts =P