Mother And Lover Harassing Adult Sons And Daughter In Law For Property

After the demise of the father in Jan 2017 due to cancer, the behaviour of the mother towards her sons and daughter in law drastically changed. Constant torture and harassment led to the children complaining to her family who suspected local friends or colleagues may be brainwashing her. Upon checking her phone for any clues it was found she had been having an affair with a man for the past 15 years to which even her husband objected. But because he had no proof and pressure from her family and friends, and protests from sons, he dropped the allegations and opted out of divorce. Now she has not only threatened to harm the sons or file fake complaints to "handle them", she has gone ahead and called the cops on them last week alleging ill-treatment. fortunately, their maternal uncle was present to handle the situation and came to their rescue. How can the sons and daughter in law protect their legal rights and stop this harassment permanently?