Robin Williams' widow has filed court papers against his three children as they fight over the late-actors estate.

In papers filed in December in San Francisco Superior Court Susan Schneider says some of the late actor's personal items were taken without her permission, the Associated Press reports.

Williams' children from a previous marriage, Zachary, Zelda and Cody, accuse Schneider of "adding insult to a terrible injury" by attempting to change their trust agreement.

In a statement given exclusively to NBC News the family say:

Robin's children want nothing more than to be left alone to grieve. The fact that they are being forced into these legal proceedings adds insult to a terrible injury.

Family statement

"The Williams' children are heartbroken that Petitioner, Mr. Williams' wife of less than three years, has acted against his wishes by challenging the plans he so carefully made for his estate," attorneys for the children said in court papers.

Schneider is asking the court to exclude the contents of the Tiburon home she shared with Williams from the jewelry, memorabilia and other items Williams said the children should have.

Robin Williams and his daughter Zelda Williams pictured in 2005. Credit: Nicolas Khayat/ABACA USA/Empics Entertainment

James Wagstaffe, an attorney for Susan Williams, said Monday that his client was only seeking guidance from the court about the meaning of certain terms in the trust.

"This is not ugly," he said. "I would not say this is anticipated to be a highly contested proceeding."

Williams died at his home in August, his death was ruled a suicide that resulted from asphyxia caused by hanging.

The trust set up by Williams for his children granted them his memorabilia and awards and some other specific personal items, according to court documents.

Schneider claims that as Williams wished for her remain at their Tiburon home, he intended only for his children to have the specific personal items he kept at another home he owned in Napa.

"Any other interpretation would lead to Mrs. Williams' home being stripped while Mrs. Williams still lives there," her attorneys wrote.

The children dispute that interpretation, saying there were no specific limits on the location of those items.

The two sides also disagree over items put in storage, watches Williams owned and his memorabilia.