Jacqueline van Maarsen said that while the use of Frank's name to fight anti-Semitism had been very effective, it inadvertently made her larger-than-life.
"Anne as a little girl was lost," Van Maarsen said during an interview in Budapest where she was presenting the Hungarian version of her book "My Name is Anne, She Said, Anne Frank" published in English in 2007.
Anne Frank was 15 years old when she died of typhus in Germany's Bergen-Belsen concentration camp in March 1945.
In her famous diary, Frank called Van Maarsen her "best friend," but the 79-year-old former artistic bookbinder said she was long reluctant to publicly claim the title.
"I wanted to have my own identity, I didn't want to go through life as Anne Frank's friend," Van Maarsen said in the Monday interview.
She said Frank was an extroverted girl whose intensity and the demands she made of their friendship were nearly overwhelming.
"She claimed me as her best friend and she didn't want me to be with other girls," Van Maarsen said. "She thought she was the center of the universe but I wasn't like that."
Dutch director Ben Verbong is making a film based on Van Maarsen's book, a project currently in the casting stage.