The future of Michael Jackson's children was thrown into question when his ex-wife emerged and won a delay in a custody hearing while she decides whether she wants to raise her two offspring.
It was the first legal move from Deborah Rowe since the entertainer's death.
Jackson's will asks for his mother, Katherine, to get permanent custody of all three of his children.
Rowe, who met Jackson as a receptionist in the office of his dermatologist, has characterised their relationship as strictly for the purpose of birthing Jackson children.
She is the mother of his two oldest children and received $US8.5 million ($A10.75 million) in their divorce, according to court records.
His youngest child was conceived with a surrogate.
She has spent very little time with her son Michael Joseph Jr, known as Prince Michael, 12; and daughter Paris Michael Katherine, 11.
But Rowe also has opposed the idea of Katherine Jackson getting custody of her children when it came up in the past.
Rowe's lawyer, Eric George, said on Thursday she had not decided whether to seek custody.
Superior Court Judge Mitchell Beckloff rescheduled a guardianship hearing for July 13 at the request of lawyers for Rowe and for Katherine Jackson, 79, who has temporary guardianship of her son's children.
The identity of the surrogate mother of the singer's youngest child, 7-year-old son Prince Michael II, has never been revealed.
Jackson's public memorial was set for 10am Tuesday at the Staples Centre in downtown Los Angeles.
Randy Phillips, chief executive of AEG Live, which owns the Staples Centre and was Jackson's promoter, said tickets would be free. He was not sure how they would be distributed.
Los Angeles City Councilman Dennis Zine said plans for the memorial are clearly moving forward, but he wished there had been more time to work out the logistics for such a huge event.
"If you can imagine 100,000 people show up and you have 20,000 capacity (at the Staples Centre), there is not sufficient room. Now you have a crowd-control problem," he said.
With the July Fourth holiday weekend "it's the worst time ... to work something out."
He also said he's concerned about the cost of police overtime for the cash-strapped city.
Jackson's brother Jermaine told Larry King during Thursday's broadcast of CNN's Larry King Live, that there will be a private ceremony for family and some special guests before the public memorial, according to show transcripts.
He added the family wants to have other memorials around the United States.
Another court hearing will proceed as planned Monday on who will take temporary control of Jackson's estate. He left all his assets to the Michael Jackson Family Trust.
Authorities also were investigating allegations that the 50-year-old Jackson had been consuming painkillers, sedatives and antidepressants.
California Attorney General Jerry Brown said his office was helping Los Angeles police investigate the possible involvement of prescription drugs in Jackson's death.