Yule is a celebration about light. It had more colors than people today have been told if you can distinguish Yule stuff of the old days and what's really Christmas stuff. Yule looks more magical than Christmas does by scenery and trees are actually used for different reasons in the old way to celebrate Yule. Yule's original decorations stand out quite well even from a distance, this is a holiday that should be shown more respect, because so many of today's people can't tell the two active holidays apart, but just guessing what a holiday means isn't the best way to change it, Yule matters just as much as Christmas itself does. Merida's part of the culture that celebrated Yule quite different in the old days, I'd respect how important this holiday was to the Celtic people. I even know what unique stuff I'd suggest to make the differences of Yule and Christmas clearer. I learned the forgotten facts of Yule with the help of a non-fiction book about Celtic symbols and holidays.
Writers of Merida's future stories are welcome to borrow my scenes found on the Zootopia Wiki with Nick Wilde as the main character but Princess Merida included, I've recently written my tale of the way I'd decorate for the day of Yule to repsect its forgotten differences. But in my short Fanon tale of Zootopia's foxes and Merida together Yule's just as happy a celebration as Christmas is. Yule Dec. 21 to Jan 1 Christmas Dec 25 or in some states of other continents Dec 5 to Jan. This stuff I know from a giant coloring book that tells you how different Christmas is celebrated in differnt states of the 8 continents, it even shows how different Santa can look.
Merida's decorations of Yule that would respect how it was celebrated where her culture is it would be easier to distinguish the two holidays. To respect the old way of the Celtic holidays, for Yule I'd suggest a bonfire because that's what they really used on holidays like Yule in the old days, Fairies, A boar, A goat, a cat, a fox, Mistletoe, cloves inside apples, Oak tree, Laurel, Yellow Cedar, Kunzite, Garnet, Ruby, Emerald, Diamond, and the flower called Blessed Thistle, plus if we add their symbol of survival the badger ( in the Celtic symbol list ) You can add magical creatures relatied to light too, such as a calm looking dragon. Yule should be respected just like the legends of Celtic states. Yule has a few symbols of the sun, but Christmas is an honored birthday.
Please let Merida celebrate Yule the old way of the Celtic if she's ever luckily in a story of a holiday celebrated by her culture. Culture and her own Princess personality, she's my favorite Disney Princess.