We don't see much of Mrs. Z. She's Homer Zuckerman's wife and Fern's aunt, but she spends most of her time indoors. And since most of this novel takes place in the barn, she doesn't get much airtime. Basically, she spends her days in the kitchen or thinking about freezers. She's super obsessed with freezers. Why? Well she's probably got a lot of things to preserve on the farm, so that they have food for the winter. We're thinking this means Mrs. Z is a smart and resourceful lady.