hi there, just a shot in the dark but i have also had this problem however it was not a garlicy it was more of a rosemary anyways i went to my local gp and she advised me to buy a brand new flannel and have a very intense wash and also to wash with dermologicly tested shower wash however in the end i now use baby soap as its for sensitive skin and the problem solved itself, im not saying this is the answer for you but it was for me and hey its worth a try good luck and i hope this works for you.,
Your daughter should see her Dr about this. It could be several things causing the odor. Does she work with chemicals at her job? Has she changed her diet in any way?