The Moral Responsibility to Friends and Family

We grant special moral considerability to people who are our friends.  Friendship comes with responsibility.  You care about your friends in ways you do not care about strangers and therefore there will come times when you have to do things for them.  But with some friends, we elevate the friendship to a level higher.  We will often say "you are not just a friend, you are family."  This seems to imply that being family grants a level of moral responsibility even higher than that we have to friends.  But we choose our friends and not our family.  Do we really owe a greater degree of moral consideration to our relatives than we do our friends?