LOS ANGELES (CNN) — A singer who participated in an impromptu duet with Whitney Houston at a party two days before Houston’s death said Monday she noticed nothing amiss and the superstar was “upbeat and joyful.”

“She did not seem disheveled. She was dancing, she was laughing. … We were having a good time,” said Kelly Price.

“What I saw on Thursday night was not erratic behavior. I didn’t see someone who was high.”

Price said the party was held to celebrate her Grammy nominations. During the party, Houston took the stage unexpectedly and sang a hoarse rendition of “Jesus Loves Me” with Price.

Price told CNN’s “Starting Point” that Houston’s voice is “naturally raspy,” but “she sounded good on Thursday night.”

She acknowledged that Houston did have champagne, which “was flowing” at the party, and said she was glad to see her friend happy. “It was a genuine moment of celebration,” she said.

“She was in good spirits leaving the club,” Price said. “Yes, she was a little messy, as I was, as every other person was at 2, 3, 3:30 … in the morning after having sung half the night, danced half the night.”

Price said she never expected to receive the call Saturday that Houston, 48, was found dead in her suite at the upscale Beverly Hilton, just hours before she was to attend another pre-Grammys party at the hotel.

“It doesn’t resonate to anything that happened on Thursday,” Price said.

There were more questions than answers Monday about Houston’s sudden death, as authorities were offering few details. The singer’s soaring voice and impressive talent had taken a back seat in recent years to her struggles with drug addiction.

An autopsy was completed on Houston Sunday, but authorities have not released a cause of death pending toxicology tests.

Speaking to reporters Monday, Ed Winter, assistant chief of the Los Angeles county coroner’s office, refused to speculate on a cause of death, saying testing is ongoing.

Beverly Hills police have requested a “security hold” on the coroner’s report, a common practice in high-profile cases that limits what can be revealed about a probe while it is ongoing. Winter on Sunday said no additional details, including what was discovered in Houston’s room, would be released.

Asked Monday whether authorities know the cause of death and are barred from releasing it by the security hold, Winter said, “We do not know (the cause) yet.” When it is known, the coroner’s office will notify police and Houston’s family, he said.

Asked how long Houston had been dead before she was found, he said she was seen by someone — a family member or someone at the hotel — within an hour of her death.

The security hold does not restrict the release of Houston’s body to her family, he said, but he said he did not know when the body would be picked up or what arrangements were being made.

A source close to Houston, however, told CNN Monday that her body will be flown to her native New Jersey, and a funeral service will be held there Friday or Saturday.

Winter said toxicology lab results were expected in six to eight weeks.

“I know there are reports that she maybe was drowned or did she overdose, but we won’t make a final determination until all the tests are in,” he said. Winter ruled out foul play and said there were no injuries to her body.

Winter confirmed reports that Houston was found in the bathtub of her hotel room. “I believe somebody removed her from the bathtub and the paramedics did CPR on her,” he said Sunday.

Entertainment news website TMZ, citing “informed sources,” reported pill bottles were found in Houston’s room. CNN could not immediately confirm the TMZ report and Winter declined to comment.

Meanwhile, a source close to the family told CNN Monday that Houston’s 18-year-old daughter, Bobbi Kristina Brown, was taken to Los Angeles’ Cedars-Sinai Medical Center twice after her mother’s death — once on Saturday night and then again on Sunday. She was treated for stress and anxiety, the source said.

Police had said Sunday that the teenager was taken to the hospital. A source close to the family said she had been released as of Sunday night and would be heading back to New Jersey, possibly as early as Sunday night. She was expected to go to the home of her grandmother, gospel singer Cissy Houston, in New Jersey, said the source, who spoke on condition of anonymity because of the sensitive nature of the issue.

Kim Burrell, a gospel singer and Houston’s friend, said she was with the teenager late Saturday, and said the girl had felt “overwhelmed.” But Burrell expressed confidence that “she’ll pull through.”

Bobbi Kristina Brown was born during Houston’s marriage to Bobby Brown, which ended in divorce in 2007.

As late as Monday morning, remembrances continued to pour in from around the world.

Nelson Mandela issued a statement extending his condolences to Houston’s family and friends. He recalled how she dedicated her performance of “Greatest Love Of All” to him during a White House dinner in his honor in October 1994.

“May she rest in peace,” the statement said.

Songstress Celine Dion, speaking on ABC’s “Good Morning America” in regard to rumors that Houston’s death might have been connected to prescription drugs, admitted she stays away from the “show business” scene because of its risks.

“It’s just very unfortunate that drugs and, I don’t know, bad people or bad influence, took over,” Dion said. “It took over her dreams, it took over love and motherhood. … When you, you know, you think about Elvis Presley and Marilyn Monroe and Michael Jackson and Amy Winehouse, I mean, to get into drugs like that for whatever reason … . What happens when you have the love, the support, family, motherhood, you have responsibilities of a mother and then something happens and it destroys everything?

“There’s something that happens that I don’t understand,” she said, “and that’s why I’m so scared. I’m scared of show business. I’m scared of drugs. I’m scared of hanging out. And that’s why I don’t do parties, and that’s why I don’t hang out. That’s why I’m not part of show business, because we have to be afraid.”

Whatever the exact cause, the grief over the death of Houston was evident Sunday at the Grammy Awards.

Host LL Cool J began his Grammy monologue by acknowledging “we’ve had a death in our family” and offering a prayer thanking God “for sharing our sister Whitney with us.”

“Although she’s gone too soon, we remain truly blessed to have been touched by her beautiful spirit and to have her lasting legacy of music to cherish and share forever,” the rapper and actor said.

Toward the end of the show, under a bright, solitary spotlight, Jennifer Hudson took to the stage at the Staples Center to perform Houston’s mega-hit “I Will Always Love You.”

Accompanied by a piano, Hudson delivered a searing, heartfelt performance that brought the audience to its feet, ending the song with one new line: “Whitney, we love you.”

Earlier, on the red carpet, Burrell told CNN she’d exchanged voice mails with her good friend Houston shortly before her death, describing her as being “in great spirits, as always.” She said she always thought of Houston as a “fighter” and a “survivor,” which made the idea of her passing all the more difficult to comprehend.

“She’s my sister and she’ll always be my sister,” said an emotional Burrell. “I love her dearly.”

Burrell told CNN Monday she is comforted by the knowledge that Houston had a solid religious foundation. She said she and Houston spoke weekly for 13 years, sometimes praying over the phone.

“Whitney knew to go to God. Whitney knew how to pray,” a tearful Burrell said Monday. “… I’m very confident that whatever her last moments were, she knew that God could be there for her. … She’s with him today.”

Burrell said she’d flown to California to join Houston in attending a pre-Grammy party Saturday night hosted by the songstress’ longtime mentor, Clive Davis. Houston died a few hours before the party took place.

On Houston’s last voice mail, left as Burrell was on the plane, she said gospel music was playing in the background.

“It’s just very hard today to see all of this,” she said. “It’s very surreal, but I’m trying very hard to be strong for her.”

Bobby Brown was swarmed by media when he arrived at Los Angeles International Airport Sunday night after pulling out of a performance with New Edition in Nashville, Tennessee, in the wake of the death.

Brown did not take any questions, and was quickly whisked into a waiting limousine.

The night Houston died, he was openly emotional during a concert in Southaven, Mississippi, said attendee and CNN iReporter Moshiu Knox, at one point asking people to say a prayer for his daughter, for his mother and “for me, because I’m going to need it.”

“Bobby was crying during his performance and at one point had to walk off stage,” Knox said.

Houston’s family issued a statement Sunday saying, “We are devastated by the loss of our beloved Whitney. This is an unimaginable tragedy and we will miss her terribly. We appreciate the outpouring of love and support from her fans and friends.”

Funeral arrangements for Houston were pending.

— CNN’s Soledad O’ Brien, Chelsea J. Carter, Mike Martinez and Greg Botelho contributed to this report.