Give visitation rights to grandparents of abused children

My grandchild was abused to the point she had to see a psycologist. Her mother didn't try to protect her. Now she won't let her talk or see her grandparents, who cared for her for three years. The mother hadn't see the child for over a year, before she came and took her away. The law needs to be changed so a child won't feel deserted.