Nona Paris Lola Jackson, 36, asked a judge to grant her joint physical custody of Jackson's 10-year-old son, Prince Michael, and 9-year-old daughter, Paris. She also claims to be the mother of 5-year-old Prince Michael II.
"I feel her evidence fails to establish any genetic relationship between herself and the Jackson-Rowe children," Superior Court Judge Robert A. Schnider said.
Schnider also denied the woman's request to nullify Jackson's marriages with Rowe and with Lisa Marie Presley, both of which ended in divorce.
Nona Jackson was heard in the courtroom through a telephone and loudspeaker. Jackson and Rowe were not present.
Jackson settled a custody fight with Rowe over his two eldest children in September. Details of that agreement have not been released. Jackson has not identified the mother of Prince Michael II.
Nona Jackson also asked the court to grant her child support in an amount to be determined by Jackson, along with possession of his Neverland Ranch and a San Fernando Valley home.
"Debbie's hospital records will prove that my kids are not hers because of DNA," she stated.
In court papers, Nona Jackson contended that "Michael and I are a sexually active couple and have been this way from the beginning." She also claimed to have written more than 3,000 songs for him.
The woman's three previous attempts to have a say in the custody battle were rejected by the same judge last November and in February and May on grounds that she had failed to notify Jackson and Rowe of the hearings.
With Wednesday's ruling, it was unclear if she had any more legal options.
"I guess it's possible she could always do something else," said Marta B. Almli, Rowe's attorney.