AWWW I'm so sorry about Daisy. You did a great thing and gave her a happy 1 week. I'm just sorry you and your family have to go through this. I hope the breeder gets what she deserves. I'm so sorry about your loss
I would encourage your son to talk about all the good things he liked about Daisy and what his favorite moments with her were. Maybe it will help him let go. How old is he?