'Mrs. Doubtfire' Star Mara Wilson Dishes on New Book, Memories With Robin Williams

— -- You know Mara Wilson from favorite films like "Matilda," "Mrs. Doubtfire," and "Miracle on 34th Street."

Now, the former child star is revealing the ups and downs of young stardom in her new memoir, "Where Am I Now?"

"The original title was 'K for Kid' because when you are a child on a film set, they put a parentheses (K) next to your name to indicate that you are a child and that you are kind of separate from everybody else, and I always felt a little like I was the odd one out," Wilson said today on 'GMA.' "... You see a lot of things on the internet. You've seen a lot of it, sort of like, 'Where is she now? Where did she disappear to?'"

Wilson, now 29, said she vividly remembers working with legendary actors like Danny DeVito and the late Robin Williams.

"I was a little nervous when I first saw him [Williams] as Mrs. Doubtfire," she said. "I was a little nervous, but he actually sang. The first time, he asked me what kind of music I liked and being the drama nerd that I was, I said that I liked musicals and he started singing, 'There is Nothing like a Dame' from 'South Pacific.' So, he was a man dressed as a woman singing a song about how there is nothing like a woman. He was a great guy. So kind, so great with kids."

When she was 10, Wilson starred alongside Danny DeVito in "Matilda" -as a character whom she said she was happy to portray.

"I was so thrilled because that was a character that I loved, that I adored," Wilson said of landing the lead role. "She was like the first girl character that I was just like, 'She is so cool. That is who I want to be,' and I did get to be her."

While Wilson was filming "Matilda," her mother died of breast cancer. DeVito made sure she was able to see the movie before she passed, Wilson said.

"I thought that my mother had never gotten a chance to see the movie, but he said he actually brought a print of the movie while she was sick, while she was dying," Wilson recalled. "They were incredibly kind people. He and Rhea [Perlman] were just like fun uncle, fun aunt and the kindest, most wonderful people, and I really owe them forever for all the good things they did for me while my mother was sick."

"Where Am I Now?" is out tomorrow.