Debbie Rowe is starting to wonder. Flexing her rights as the surviving – though not custodial – parent of Michael's eldest kids, Prince, 13, and Paris, 11, Rowe is "quite upset" to hear about antics involving a stun gun at the Jackson family compound, her close friend Marc Schaffel tells PEOPLE.
The trouble focuses on reports that Michael's 13-year-old nephew Jaafar, who also lives with the King of Pop's mother Katherine Jackson, bought the weapon online and may have tried to harm Michael's third child, Blanket, 8.
"Right now she is mortified and very, very concerned over the welfare of her children and what they are being exposed to," her pal Marc Schaffel tells PEOPLE.
The L.A. County Department of Children and Family Services has reportedly visited the Jackson's Encino, Calif., home at last three times. Katherine's attorney contends Blanket was never threatened and that Paris never saw the weapon. But Schaffel says that Rowe was informed that Paris and Prince both saw the gun.
Rowe, who has not seen the children since Jackson's death, "will take steps to make sure this doesn't happen again," but in the meantime she is "waiting to see what Children and Family Services says first," says Schaffel.