The world may have been shocked to hear of Prince's death on April 21, but his sister says she had been anticipating it for a long time.

But she didn't say if she knew he had been using powerful prescription painkillers.

During an interview for Thursday's Paisley Park museum opening, Tyka Nelson toldEntertainment Tonight that when she got the phone call that morning, "It wasn't hard at all," she said in a matter-of-fact way. "It was a two-word phone call: 'He's gone.'

"And I knew who he meant. I hung up the phone. An employee of Prince called. I have been preparing for two years, so I knew that it was coming."

An abbreviated autopsy report later established that Prince died of an accidental overdose of the powerful prescription painkiller fentanyl, although it is still unclear where he obtained the drug and whether a crime led to his death. Police in Carver County, where his Paisley Park compound is located, are still investigating.

Tyka, 56, is Prince's only full sibling. She was the one who requested that a judge appoint an administrator for his estate after no will could be found. Regarding thestatus of the estate, she said, "I think we're finally on the last leg. We're through the 195,000 people who claim they're related."

She added that she meets with the other established relatives on a weekly basis and the vibe is friendly. "People want to think we're fighting so I'll make jokes about it, like 'What are we fighting about today?' "

Though her choice of words may suggest that Nelson was aware of her brother's use of prescription painkillers, drugs never explicitly came up in the interview.

Instead, her explanation for why she was prepared for his death was that Prince himself seemed to sense the end was near.

"He said it a couple of years ago: 'I've done everything that I've come to do,' I was crushed for about two years."

She is well aware that the wound is still raw for many fans.

"I've had two years to deal with it," she explains, "but there's a lot of people that have only had from April to now, so I guess I would say give it another year and a half and maybe you'll be where I'm at. I'm sorry that you're hurting."

The silver lining for Tyka: "He's not physically here but through Paisley Park and his music, he'll live on forever."

Contributing: Maria Puente