Communities of the Canidae Sapiens species live in a meritocracy revolving around knowledge and technology, therefore even their children pick up an occupation and develop strong aspirations early on.
Young Sif here aspires to be an intel gathering specialist (i.e. a spy) and practices with a group of like-minded neighborhood children every day, much to the chagrin of Lago and Emil who frequently find themselves stalked and playfully ambushed. Hopefully she will lose her chaotic streak in time for adulthood, where it turns out that Lago is in need of a competent team of sp- ... intel gathering specialists.
Her helmet is an heirloom from the Departure, the fateful rebellion against mankind that her elders decided in their favor.