because she likes freedom and in the end fights for what she believes and love (family, freedom and kingdom).

Even though she is Scottish, she as a really green pallet. Scottish and Irish aren't too similar, but I think both of them celebrate St. Patrick's Day.

well, because of her relationship with her mom

The film is defined by her relationship with her mom.

Because of her mum. I don't think any of the others fit her particularly well, although she does wear a lot of green and I can picture her celebrating St Pat's Day so an argument could be made for that too.

Lol, I love how St. Patrick's Day is winning just because she Scottish.

If anything, Merida represents Halloween best considering how vile and evil she is.

Might be coz she's Scottish? She has green colors and I can imagine her celebrating this festival.