Lisa Marie and Michael shared daughters Harper and Finley.
Priscilla Presley makes an appearance at her twin granddaughters middle school graduation but remains separate from the family.
The twins' 33-year-old sister, Riley Keough, did not attend the ceremony.
Michael Lockwood also signed on to the agreement.
Harper Vivienne Ann and Finley Aaron Love are currently 14 years old.
Michael Lockwood will likely be granted full custody of the twins he shared with Lisa Marie Presley.
Lockwood filed the documents in court on Thursday.
Lisa Marie Presley's ex-husband, Michael Lockwood, opens up about her untimely death and how their twins will carry on her legacy.
At the time of Lisa Marie Presley's death, she had 60% custody of her twins and ex-husband Michael Lockwood had 40% custody.
