Here is the true story/update
For the true story visit the movies based on true stories database
URL link: http://www.motherknowsbestmovie.blogspot.com/
Mother Knows Best is based on the true story of Lee Goldsmith of Boca Raton, Florida. In February 1989, the then 67-year-old retiree tried to have her son-in-law David Brownstein killed.
McLeod, Michael. (January 10, 1993) “Lee Goldsmith, In Jail For Hiring A Hit Man” Orlando Sentinel (http://articles.orlandosentinel.com/1993-01-10/news/9301070848_1_lee-g oldsmith-daughter-jail)
Walsh, Barbara. (October 3, 1993) “Lee Goldsmith: Hard Time For A Grandmother” Sun Sentinel (http://articles.sun-sentinel.com/1993-10-03/features/9309160551_1_lee- goldsmith-prison-kathy-willets)
Walsh, Barbara. (June 18, 1995) “Grandma In Murder Plot To Be Freed” Sun Sentinel (http://articles.sun-sentinel.com/1995-06-18/news/9506170306_1_arleen-b rownstein-brownstein-s-mother-david-brownstein)
Curry, Traciy. (2004) “Mother Knows Best” Movies Based on True Stories (Internet Archive: http://web.archive.org/web/20091024231155/http://geocities.com/murder_ stories/mother_knows_best_movie.html?1045403486890)
Curry-Reyes, Traciy. (2009, 2011) “Mother Knows Best” Movies Based on True Stories Database (Blog: http://www.motherknowsbestmovie.blogspot.com/)