In life, Tia Victoria was a shoemaker like the rest of Rivera family, and apparently specialized in crafting huaraches (a type of sandal). She wore glasses and - if her personality carried over to the afterlife - was prim, respectable, and intellegent. She was the first of Miguel's deceased relatives to realize that he was neither dead nor alive when he first appeared to them.
She also apparently had something of a no-nonsense attitude: When Miguel first glimpses the Land of the Dead, he recounts how he always thought it was just a story that adults told children, just like how he didn't believe their stories about vitamins. Tia Victoria dryly remarks, "Miguel, vitamins are a real thing."