Riley Keough Is 'Very Protective' of Sisters Finley and Harper, 14, After Mom Lisa Marie Presley's Death: Source

Riley Keough doesn't mess around when it comes to her role as "big sis."

Since her mom Lisa Marie Presley's death on Jan. 12 at age 54, a source close to the Daisy Jones & the Six actress, 33, tells PEOPLE in this week's cover story, on newsstands Friday, that she's been "very protective" of her 14-year-old twin sisters, Finley and Harper Lockwood.

"Riley has always been close with her sisters," says the source. "She wants the best for them. They have been surrounded by drama for years."

While Riley and the twins appeared a united front with their extended family — including grandma Priscilla, uncle Navarone Garibaldi Garcia and the twins' dad Michael Lockwood — at their mom's public memorial at Graceland on Jan. 22, sources say there was tension brewing behind the scenes.

"Michael was not invited," says a close friend of Lisa Marie's. "He came to Memphis under the pretense that he had to chaperone the twins — and he forced his way in with Priscilla's help. The last thing Lisa Marie would have wanted was for Michael to be there."

RELATED: Inside Priscilla Presley and Riley Keough's Fight Over Lisa Marie's Trust: 'They Don't See Eye to Eye'

In the weeks leading up to her death, Lisa Marie and Priscilla, 77, had seemed close at various events while celebrating Baz Luhrmann's Oscar-nominated Elvis biopic. But multiple sources say the two were barely speaking, and their relationship had been fractured since Lisa Marie's split from Michael, 61, in 2016.

After the breakup, the exes were embroiled in a nasty custody battle over the twins that lasted until October of last year. Friends say Lisa Marie resented that Priscilla sided with Michael, and the tension trickled down to Riley. (Her dad is Lisa Marie's first husband, singer Danny Keough, 58.)

"Riley was always on her mom's side when it came to Michael," says the Riley source. "It bothered her that her grandmother and Michael flew to the funeral together."

Lisa Marie Presley rollout
Lisa Marie Presley rollout

Steve Cohn/Shutterstock Riley Keough, Harper Lockwood, Lisa Marie Presley, Finley Lockwood, Priscilla Presley

The drama exploded four days after the memorial when lawyers for Priscilla filed a petition in Los Angeles questioning the "authenticity and validity" of a 2016 amendment to Lisa Marie's living trust. The change had removed Priscilla and Lisa Marie's former business manager Barry Siegel as cotrustees and given control of the trust — the Graceland mansion and a 15 percent stake in Elvis Presley Enterprises (EPE), which together brought in a reported $110 million in 2022 — to Riley and Lisa Marie's son Benjamin Keough, who died by suicide at age 27 in 2020.

Priscilla, who claims she didn't know about the 2016 amendment until after Lisa Marie's death, argued it should be voided because of several factors, including that Lisa Marie had not informed her of the changes as required by the terms of the trust. But Lisa Marie's friend claims "there's zero question" what her wishes were: "Lisa wanted Riley and Ben to be the trustees" — and for all her children to be the beneficiaries.

Now, as they mourn, Riley and Priscilla are barely speaking, according to multiple sources. Says a Presley family insider: "They do not see eye to eye."

(Reps for Priscilla, Riley, Lockwood and Siegel did not comment for PEOPLE's cover story.)

RELATED: Priscilla Presley Makes First Red Carpet Appearance Since Lisa Marie's Death amid Trust Battle

If the 2016 amendment is voided in court, Priscilla and Riley would be cotrustees.

"Priscilla doesn't want Riley solely in charge, because then she has no say," says the family insider. "Meanwhile, Riley doesn't want Priscilla to butt in."

Adds the Riley source: "It's a very sad situation. Riley is shocked Priscilla is contesting the amendment."

Lisa Marie Presley rollout
Lisa Marie Presley rollout

Michael Kovac/Getty Priscilla Presley and Riley Keough

In a Feb. 3 statement, Priscilla maintained she is acting with "integrity and love," and a Lockwood source says the matriarch remains close to Michael to "be a part of her grandchildren's lives."

With a court hearing scheduled for April 13, sources say Riley is focused on her acting career — she stars in Amazon Prime Video's new limited series Daisy Jones & the Six — and Elvis' first great-grandchild. At her mother's memorial, Riley's stuntman husband, Ben Smith-Petersen, revealed that they had had their first child in 2022.

"Lisa Marie's death has been very painful for Riley, but welcoming her baby girl has been blissful," says the Riley source. "[Her] daughter brings her joy. She loves being a mom."

Meanwhile, Priscilla has co-created Netflix's Agent Elvis, an animated series that debuts March 17, and she's the subject of an upcoming biopic directed by Sofia Coppola.

RELATED: Friend Says Lisa Marie Presley Wanted Trust to Go to Kids as Mom Priscilla Presley Contests Will

As Priscilla and Riley vie for control of Elvis' financial legacy, the King of Rock and Roll's close friend Jerry Schilling hopes to see one part of the mythology remain intact.

"I would like for Graceland itself to stay as it has for the last 45 years, as a piece of history captured in time," he says. "I'd like to see it as Elvis left it, as he decorated it, for the generations of Presley children. It's the White House of rock and roll."

For all the details on the fight over Graceland, pick up this week's issue of PEOPLE, on newsstands everywhere Friday.