Forced to appear in court, CASEY ANTHONY will take the Fifth in the defamation case against her.

Anthony is required to show up in person to face allegations of defamation in Zenaida Gonzalez's civil lawsuit against her, but reports the exonerated murder mom plans to plead the fifth.

Casey, 26, has been fighting hard to not have to appear in the courthouse for the trial, and according to a pal of her brother, Lee Anthony,she does have to appear she doesn't plan on testifying.

"Lee will have to testify, but Casey is hoping she'll find a way out of it.

"She wants to just show up to court for one day, plead the fifth, and then never have to go back to the courthouse."

However, because Casey is appealing her lying convictions — which will be heard separately — the only way she will be able to plead the fifth is if those convictions get overturned, otherwise she won't have that option.

"Casey's entire family just wants all of this to be over. It's been three years of hell for them," the insider said.

"They will do whatever it takes to get Casey out of all of this. But what they don't realize is that there are rules and Casey will have to follow them. They're not adequately prepared yet for if Casey's plan to plead the fifth doesn't work."

Zenaida is suing Casey for defamation after the Florida mom told cops that a woman with the same name had kidnapped her missing daughter, Caylee.

Casey's lawyers tried to argue that it wouldn't be safe for their client to appear in public, but a judge ultimately ruled she will have to show up.

Her legal team then argued a change of venue because "Ms. Anthony cannot get a fair trial in Orange County."

Anthony's civil attorney, Charles Green, told Judge Lisa Munyon during a brief hearing Tuesday morning that a change of venue was necessary because it's an "impossibility, I submit, that Ms. Anthony can get a fair trial in Orange County. We had hoped that the publicity in this case would subside after the criminal case. It has not."

"Casey Anthony could potentially be held in criminal contempt if she fails to appear," Zenaida's attorney John Dillis said. "I wouldn't tempt this judge if I were her."

The civil trial is docketed for January, 2013.