If the birth parent dies, the rights of the surviving co-parent are very precarious. A power of attorney or health care authorization are no longer effective upon death. That leaves the co-parent without any legal standing in relation to the child and therefore without the ability to make legally binding decisions about the child's welfare.
A birth parent who wants the co-parent to raise the child in the event of her or his death should certainly include such a provision in a will. The birth parent also should make her or his wishes known to the family members of both birth parents and make every effort to enlist their agreement. In North Carolina the parent's recommendation will be a "strong guide" for the clerk who appoints the guardian, but the clerk is not bound by it. The clerk will make whatever decision she or he thinks is in the best interest of the minor child.
A co-parent may petition to become the child's general guardian. If the surviving birth parent and the family of the birth parents all agree that it would be in the best interest of the child for the co-parent to be the guardian, the clerk is likely to grant the petition. However, if the surviving birth parent or appropriate family member fights to have custody of the child, it will be a difficult battle. Again, it is important to consult with an attorney experienced in this area or check with NC GALA for a referral.