Egress/Ingress right of denial

My 75 year old Mother is one of 4 remaining siblings 4 out of 13 who has maintained and paid taxes on heir property (house & 5.7 acres) in Isle of Wight County, Virginia for 50+ years. Years ago prior My Grand mother sold a plot of land on the same property to my Uncle for $1200 and he built a home and raised his family. He remarried and died. In his generic Will he gave his widow lifetime rights to the home on the purchased plot. My uncle’s daughter and husband lived in the house and paid escalating rent to the Widow. She did no upkeep and they had to purchase things like a new refrigerator, stove etc over time. The plot is land locked meaning they have to use the driveway on the other family heir property to gain access to my uncle's property plot. The use of the driveway was a courtesy because it was family. My uncle’s daughter and husband could no longer afford the high rent and have moved out. The Widow has vowed that she will not rent the property to anyone in our family and will rent to others. My mother is concerned about now having strangers on the land and that they will be crossing the heir property to gain access. She does not want this to happen. How can we in accordance with law make sure the widow has to put in another drive way to egress the plot? By the would she would have to purchase additional property from the heir property in order to gain access to the public road. How do we petition the court for this order? How do we mark off the property line so they know what is what? Now that family will not be living there we don’t want others tearing up the property. By the way because my uncle purchased land from my Grandmother, the widow has vowed to come after his share of the heir property. That is another can of worms…There are five generations of heirs! I really don’t know if there is any defined easement??? I only know that driveway has been there for the last 75+ years.

I is best if all parties can agree and amend the deeds etc.

But if you cannot you may go to court and a court will order some access. The court is generally not going to permit a parcel of occupied land to become landlocked--especially with the long history of use that you describe.