Debbie Rowe and Katherine Jackson
Splash News Online; Landov
04/21/2014 at 10:55 AM EDT
Despite reports that Debbie Rowe, 55, is now seeking custody of Michael Jackson's three kids, a source close to the family says the children's grandmother, Katherine Jackson, who currently shares guardianship
of Prince, 17, Paris, 16, and Blanket, 12, with their cousin T.J. Jackson, is not concerned.
"Katherine isn't worried about it. It will never happen," says a source. "She's not heard a word about this from Debbie Rowe officially or unofficially and she hasn't been contacted by her lawyers."
Rowe's lawyer, Eric George, and the Jackson family lawyer did not respond to requests for comment.
According to TMZ
, Rowe – who recently got engaged
to Michael's former producer – is concerned for the three children and told a friend that "Katherine's not connected with the kids or involved in their lives."
But Michael's brothers, Jermaine, Tito, Jackie and Marlon, counter that claim, telling PEOPLE in a statement: "Our only desire is to see our niece and nephews continue to go on with happy, healthy and safe lives. We will do everything and anything with in our power to help make that happen. They are well-loved and well taken care of."
In response to reports that Rowe is seeking custody, they said, "We are quite taken back that Ms. Rowe has decided now to enter their lives, after she abandoned her children many years ago for money."
According to a source, all three kids are looking forward to an upcoming summer vacation together although a destination has yet to be decided. Paris, who is in Utah at boarding school
, will be returning home, while Prince starts his senior year in high school in the fall and is interested in going into producing and directing
Reporting by CHAMP CLARK and CARLOS GREER