Do you think your daughter may want to test the idea that garlic changes the flavor of eggs? And, if it changes the flavor, is that good or bad?
Clemson University poultry scientists did research about 10 years ago on controlling the odor from laying houses by putting garlic in the layer feed. They used garlic powder at an "incredible" 3% of the feed!
I have given garlic powder to my hens at a rate of 1/2 teaspoon to 2 cups of feed. That is much lower than what Clemson was doing. Still, think about how much your food would taste of garlic if you put 1/2 teaspoon of garlic powder in each and every 2 cups. My hens, themselves, smell a little of garlic but I don't notice any "off" flavor or smell to their eggs.
It does decrease the odor of the coop during the summer but it also seems to increase their consumption of the feed. They seem to like the garlic.
Here's what the Clemson people learned also: "The researchers have already conducted taste tests and found that people preferred the eggs produced by the garlic-eating hens."
Garlic Perfumes Poultry Houses. ScienceDaily.
It's a finding she could test herself. She would need to carefully weigh her feed and the garlic powder so as to be able to say what percentage of garlic is in the hens' diet. Then she could cook eggs from garlic-fed hens and eggs from hens that were not fed garlic and do a taste test with volunteers.
Steve