Robin Williams wrote a letter to a school principal urging they 'rethink' the expulsion of a 'Mrs. Doubtfire' child star

• The "Mrs. Doubtfire" child stars reunited for the first time in over 30 years for a podcast.
• They shared behind-the-scenes stories about their late costar, Robin Williams.
• Williams intervened after one was kicked out of high school.

One of the child stars of "Mrs. Doubtfire" revealed that Robin Williams went to bat for her after she was expelled for taking time off to star in the blockbuster comedy film.

"Mrs. Doubtfire" starred Williams as a divorced dad who hatches an elaborate plan to imitate a female housekeeper so he can work for his estranged wife and see his children. The much-loved movie took home $441 million at the box office worldwide, making it the second highest-grossing film of 1993.

Lisa Jakub, who starred as the eldest daughter of Williams and Sally Field's characters in the movie, recalled how the late screen legend stepped to get her high school to "rethink" their decision while appearing on the "Brotherly Love" podcast alongside Mara Wilson and Matthew Lawrence, who played her on-screen siblings.

"I got thrown out of high school on 'Doubtfire,'" Jakub told her costars. "I'm Canadian. I was attending high school in Canada, then I left for four months to go film the movie."

Even though she had "three hours of schoolwork on set every day" to make up for the 9th-grade lessons the teenager was missing, Jakub's high school was unhappy with her on-set education.

"We were a couple of months into filming, and my school in Canada sent a note saying: 'This isn't working for us anymore, don't come back.'"

"It was just so heartbreaking because I had this life that was very unusual, and that was the one normal thing," she said.

According to Jakub, when Williams saw she was "devastated" by the decision, he came to her defense over her education and did his best to reverse the decision.

"The amazing thing was Robin saw that I was upset — he asked me what was going on," the actor explained. "He wrote a letter to my principal saying that he wanted them to rethink this decision and that I was just trying to pursue my education and career at the same time, and could they please support me in this."

Unfortunately, the principal of Jakub's school stayed firm in their decision.

"The principal got the letter, framed it, put it up in the office, and didn't ask me to come back," Jakub continued. "Amazing."

It wasn't the only time Williams put pen to paper to advocate for his younger costars. Lawrence shared that the actor also wrote a letter of recommendation to help him get into the University of Southern California several years after their work on "Mrs. Doubtfire."

But Jakub's expulsion had a knock-on effect on her adult life. The now 45-year-old left acting behind in 2000 and said it took her years to catch up.

"When I left LA at 22, I did not have a high school education. I hadn't graduated," said Jakub.

Speaking to Business Insider last year on the 30th anniversary of the movie, "Mrs Doubtfire" director Chris Columbus said that he and Williams began discussing the possibility of a sequel in 2014.

Williams' death that same year shut down any further conversation about a follow-up. "There will never be a sequel to 'Mrs. Doubtfire,'" said Columbus.