It would be very unusual for grandparents to be successful in blocking the relocation of a child who is in the custody of the sole surviving parent under Louisiana law. However, if they have managed to obtain a restraining order, it would be a mistake for the mother to relocate without hiring an attorney to respond and to attempt to have the restraining order dismissed.
Grandparents are entitled to pursue custody of their grandchildren as well as visitation, but as you describe the situation it seems it will be difficult for them. The first thought that comes to mind is whether they at any point prior to the proposed relocation attempted to gain custody or visitation. If they did and were unsuccessful they'll need to show something more than the fact that your fiancee is relocating. If they did neither I would suspect, unfortunately, that this has more to do with the manner by which they are dealing with the death of their son.
This response is not intended to create an attorney client relationship and is based on the limited information available at the time of the response. Before acting on anything stated or referenced in this response you should consult with an attorney of your choosing and go over the specific details of your legal circumstances.
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