Paris Jackson Tweets: 'Grandma's Here!'
"grandma's here! #thankyougod," Paris wrote on Twitter early Thursday morning.
Paris, 14, had apparently been losing sleep over the mystery of Katherine's recent whereabouts and well-being.
"5 hours of sleep last night, been awake for 23 … time to #hibernate," she wrote in a follow-up note.
Katherine's return to Los Angeles is the latest development in what has been a bizarre Jackson family crisis centered on Michael's will and the welfare of his children.
Five of the late pop star's siblings are claiming his will was a fake, and that Katherine, 82, was being manipulated by the executors of his estate, worth more than $1 billion.
Police were called to Katherine's home on Monday to deal with a physical altercation between two unidentified people, amid reports that Janet, Randy and Jermaine Jackson tried to take Michael's kids Prince, Paris and Blanket from the compound.
On Wednesday, a judge temporarily removed Katherine as the children's guardian, naming Michael's nephew TJ as the replacement.
There have also been suggestions that Katherine was being kept away from the kids against her will, though she claimed she was simply on vacation in Arizona.
"There are rumors going around about me that I have been kidnapped," she told ABC News. "I am here today to let everybody to know that I am good and fine ... My children would never do anything to me like that."