Hauser's husband, Anthony Hauser, who went on television, pleading for them to return home, said that he believes his wife saw X-rays of Daniel that scared her.
"I know you're scared and I feel that you left out of fear, maybe without thinking it all the way through," Hauser said.
Authorities had promised Colleen Hauser in a May 21 press conference that they would not take law enforcement action if she showed "a good faith effort" to come back.
Daniel's court-appointed attorney, Phil Elbert, said Daniel has seen the most recent X-rays of his tumor, which show that the tumor is a white, see-through mass. Previous X-rays had shown a dense, black mass, according to the AP.
Elbert said Daniel will continue chemotherapy if he has to, even though he doesn't want to.
In an affidavit, Colleen Hauser said she seeks the court's forgiveness for fleeing with her son and thanks the judge for allowing Daniel to stay with the family after the two returned from California.
"It is so important to Danny that he be surrounded by his family," the affidavit read.
The Associated Press contributed to this report.