Understanding Evey means understanding what it's like to be a mage born into a family of apostates -- what it's like to always run and hide, not make friends, constantly move. Having no real home, no wealth or much possessions, it shapes the person a certain way.
Evey always copes with humor, but even then, there is something she never jokes about -- her family. It's all she has ever had; it's all she really needs. It's in her blood by the time she and the twins lose their father. It weighs on her when she watches the ogre smash her baby sister's skull to the ground; it forces her to work for a better life, accept shady deals and even go underground for weeks just for the chance to provide for her annoying little brother and their mother.
Even when it's supposed to be about mage rights and templar arbitrariness, it isn't. It's always about her family.