S.D.
First, it's not your place to say anything to your husband's family. Tell him how you are feeling and maybe he will say something. I know how you feel, my family was farther away when I was in school and they visited me more than his parents every did and actually showed more interest not only in my work, but than in his than his parents! It's just the family dynamic he grew up in. It still makes me mad some times when I see them spending so much time and energy on his older sister her son than on my husband and his son (and me).
However, you have every right to say something to your friend. Tell her that, as god mother, you hoped that she would have more contact with your daughter. Also, tell her about how your in-laws aren't spending much time with her - make it a vent session and maybe she will get the idea.
Good Luck!