This is really interesting, but the whole thing seems rather sudden. It would greatly improve the story if you had some buildup to the family's change of heart. However I always like to see Harry and Dudley developing a relationship so I'll take what I can get ;)
Author's response
Thanks! It's cough actually my first fanfic, so I did the typical novice thing and pushed it to get it to where I want. Now I'm slowing things down...