Ask Fr Francis

You could do that, or you could tell them that they must first bring the holy card to their priest and ask him to bless it. I personally would prefer that since many kids would probably ignore the card or not treat it with respect and devotion. But if I give them a task, then may be a few more would actually do it and both they and their parents might learn something from the task. And if they have taken the first step of getting it blessed, may be they would be more serious about developing a devotion and using the card to pray more.