Madelyn Pugh Davis, one of Lucille Ball's longtime writers, died at her home in California at age 90 on April 20, 2011. Davis had been Lucy's writer for more than 40 years, starting with My Favorite Husband in 1948 all the way through Lucy's last short-lived television sitcom, Life With Lucy in 1986. She was truly amazing, and without her, nothing "Lucy" would be what it is today. All of us Lucy lovers need to be truly thankful to her, as well as to her many writing partners over the years: Jess Oppenheimer, Bob Carroll, Bob Schiller, and Bob Weiskopf.
Here is her obituary from the New York Times:
Madelyn Pugh Davis, Writer for ‘I Love Lucy,’ Dies at 90
And from the Los Angeles Times:
Madelyn Pugh Davis dies at 90; 'I Love Lucy' writer