Sorry to hear about your grandfather.The beneficiaries who inherited the landlocked property have a right of ingress and egress (entrance and exit) to and from their property.  They can go to court and obtain an easement by necessity which is the right of way affecting your property.Although the court will consider your arguments regarding the safety of your children, it is unlikely that you will prevail because the landlocked property owners have a fundamental right to enter and exit their property.  Therefore, the easement by necessity will be granted to those property owners.  You should argue that for the safety of your children, the easement by necessity (right of way) should be as narrow as practical for the safety of your children and to limit the adverse impact on your property.