Tort Liability of Property owner?

My brother wishes to hold his daughter's wedding on pasture/farmland property owned by my mother. There is no road, path provision for people walking or driving to the location...What is my mother's liability if there were an accidental injury to someone or their vehicle, or both, attending the wedding and they filed suit?

She or her insurer could be liable--just as if they were in her home.

You could buy coverage just for the event possibly if no coverage exists.

Is there a specific type of rider that should be purchased?
Is there an "absolute" that prevents her from any and all liability?
Does the policy have to be purchased from her present insurer?
Can she be turned down?

[judg4]

They don't have to agree to it; that is subject to negotiation. But at some price insurance always exists.