It’s no secret that Hufflepuffs are very tight-knit. What’s important to one tends to important to most. Everyone in Hufflepuff knew of Credic’s feelings for Cho so, when he died, the Hufflepuffs began keeping an eye out for Cho in Cedric’s place. They never let her know, but they were the reason she never went more than a day without having found something she lost. Or the reason food sometimes appeared before her when she skipped meals. Even during the war, while Hufflepuffs looked out for everyone, they kept special watch out for Cho, knowing that Cedric wouldn’t be happy reuniting with her so soon.