Gee you are in a tough situation. I here you on family not liking a child because they don't look like one of their own. My eldest is very much like his father, however my next boy is basically my side of the family. My In Laws adore my eldest son but I feel like my next boy just gets left out all the time. Unfortunately my 3rd son is even more of a spitting image of his father so he now gets all the attention.

I don't think you are being selfish in asking for you husband to make your family his priority. I know my SIL (on DH side) has married a man who is selfish and puts himself first and they are about to have their 3rd child. And I tell you what it isn't up to my DH to fill the void that those children's own father doesn't. That being said we certainly love them but they are not our responsilbility. And my SIL is also very vague and self centred, parenting to her is just about the funny things kids do/say not actually trying to teach them correctly.

I think your in laws are so very very wrong in pointing out it is DH nephew, you are his wife. (must say though I think I will feel a bit differently to my own brothers children when they have them to my DH's) I think maybe you could foster something where by your nephew comes to your house and plays with your children etc, I don't see any reason why your DH should be off with the nephew on his own, I feel that is just wrong.

Hope that makes sense