Old wife thrown out for another women how can she claim maintenance

My neighbor is 65 years old and has 3 daughters and 1 son. All four children are married but son lives with her. Her husband (66 years old) has an affair with a woman (recently her husband has died) who was their tenant but now has her own house. This house where they all live belongs to her husband. Now he is saying that either he will give this house to that woman or sell it and will live with her. She sacrificed all her life for her children and now at old age, he thrown her out of his life. Is there any way so that she can stop her husband from selling this house or from giving to that woman. Most important, he used to keep all rent (from house) with him, never give even single penny to her wife. She is totally dependent on her son. What she should do?