"Diana is extremely concerned about Paris," a source close to the situation revealed.
"She was stunned that Paris attempted suicide and has vowed to make sure she gets the help she needs."
King of Pop Michael Jackson stipulated in his 2002 will that Ross get custody of his children -- Prince Michael, 16, Paris, 15, and 11-year-old Blanket -- if his 83-yer-old mother were ever to become incapacitated.
"Diana absolutely isn't going to make a move for custody of the children after Paris' suicide attempt," said the source.
"She only wants what is best for them. Diana has tremendous respect for Katherine and all that she has done for the children and told her, last week when they spoke, that if she needed anything, she stands ready to help in anyway."
Diana is also "planning on visiting Paris after she is released from hospital -- and it will be out of the glare of the media," the insider revealed.
As Radar previously reported, the 69-year-old The Supremes diva spent time with her godchildren last summer in the midst of the Jackson's bitter family feud, when late pop star's siblings cut off contact between the kids and Katherine.
"Diana told them they could call her anytime they needed anything," an insider said.
Interesting fact: Ross -- who at age 25 met a 10-year-old Jackson in 1968 -- must be notified if there are any issues related to the children, because of the "Thriller" singer's will.
"If any of my children are minors at the time of my death, I nominate my mother, Katherine Jackson as guardian of the persons and estate of such minor children," Jackson, who died on June 25, 2009, after suffering a cardiac arrest at his home, stated in his will.
"If Katherine Jackson fails to survive me, or is unable or unwilling to act as guardian, I nominate Diana Ross as guardian of the persons and estates of such minor children."