As this article mentions Michael Jackson's mother was given temporary guardianship of all three of Michael's children. For Debbie Rowe the mother of two of the children her address was listed as "unknown". Strangely instead of unknown regarding who the mother of the 3rd child was the Jackson petition had said none regarding the mother.
A court hearing is schedule for August 3 to determine where the who is best for the children to have as their guardianship. Ms. Rowe's attorney has indicated she would likely contest custody of the children and guardianship of her two children with Michael based on being the natural parent but gave no further information.