In California, under Family Code section 3100, a family court can grant reasonable visitation rights to the grandparent of a minor child. This applies in instances where a minor child is deceased, but can also apply in other scenarios. When fighting for your rights, you must prove that there is a preexisting relationship between you and your grandchild. Keep in mind that the court will always keep the best interest of the child in mind when determining any visitation or custody agreements.