Pauline Phillips --the woman who founded the "Dear Abby" advice column -- died yesterday at the age of 94. A rep for Phillips tells TMZ ... Pauline had been battling Alzheimer's disease. Pauline's daughter, Jeanne -- who took over the "Dear Abby" column -- says ... "I have lost my mother, my mentor and my best friend.

"Dear Abby" first appeared in print in 1956  -- and eventually grew to a daily readership of 100 MILLION. Pauline's twin sister was advice columnist Ann Landers -- who died in 2002 at the age of 83.

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