- NEW: "My mom would fight any battle for us and for her honor," the singer's son says
- NEW: Mourners pray in silence for victims of last week's school shooting in Connecticut
- Manager: "Jenni...made it OK to be from nothing with the hopes of being something"
- Godfather: "Her blunders...made us know that she was one of us"
(CNN) -- A bright red casket with butterflies on it was center stage in a packed Los Angeles auditorium Wednesday as thousands of mourners bid farewell to Mexican-American singer Jenni Rivera.
Brassy music rang out in the Gibson Amphitheatre, which holds 6,100 people. Photos showing Rivera with her family flashed in the background. Fans chanted her name, waving white roses in the air.
"Jenni made it OK for women to be who they are," longtime manager Pete Salgado said, choking back tears and drawing cheers from the crowd. "Jenni also made it OK to be from nothing with the hopes of being something."
Rivera, whose soulful ballads sold out concert halls and made her a household name to many, died in a plane crash in a remote, mountainous area in northern Mexico on December 9. The crash killed everyone aboard the small plane, including Rivera's publicist, lawyer and makeup artists.
Read more: Rivera crash puts spotlight on charter jet safety
Family members called Wednesday's ceremony a "graduation to heaven," saying the singer's powerful spirit would live on and urging fans to keep her memory alive.
"I am sure that my sister is singing now," said Juan Manuel Rivera, one of her brothers.
Another family member, Gustavo Lawrence Rivera, asked crowds to applaud for "Jenni, the eternal diva."
Nicknamed "La Diva de la Banda" or The Diva of Banda Music, Rivera was a musical powerhouse with her Spanish-language performances of regional Mexican corridos, or ballads. Rivera sold 15 million records, according to Billboard, and recently won two Billboard Music Awards, including favorite Mexican music female artist.
She was reportedly on the verge of a crossover with an English-language sitcom inspired by the success of "I Love Jenni," a Spanish-language reality TV show on Telemundo's mun2 network.
'Perfectly imperfect'
The singer was also known for her tumultuous personal life -- something her friends and family acknowledged in Wednesday's ceremony.
Both Salgado and one of Rivera's daughters described her as "perfectly imperfect."
Pepe Garza, the singer's godfather, said her honesty and openness made friends and fans adore her.
"Above all we love her for her imperfections," he said. "It was her blunders that made us know that she was one of us."
Born in Long Beach, California, to Mexican immigrant parents, Rivera released her debut album in 1999, according to her website.
She followed that up with two more albums, including the 2003 album "Farewell to Selena" -- a tribute to slain Tejano star Selena Quintanilla -- that increased her popularity.
She was nominated for Latin Grammy Awards in 2002, 2008 and 2011. In October, People en EspaƱol named her to its list of the 25 most powerful women.
Rivera became a single mom at the age of 15 and was the mother of five children, all of whom spoke at Wednesday's memorial.
In 2009, Rivera made headlines when she was detained at the Mexico City airport with tens of thousands of dollars in cash. A year later, she made headlines again with the marriage to former baseball pitcher Esteban Loaiza, who played for the New York Yankees and the Los Angeles Dodgers. They later divorced. It was her third marriage.
Her over-the-top lifestyle was chronicled in "I Love Jenni" on Telemundo. The show began airing on mun2 last year, and featured her life on the road, balancing the duties of motherhood and stardom as she toured Mexico and the United States.
"My mom would fight any battle for us and for her honor, even if there was no one to fight," her son, Trinidad "Michael" Angel Rivera recalled Wednesday. "Sometimes it seemed like she was just waking up to fight the day, to prove that in those 24 hours, she could make 35 hours worth of work."
He asked audience members for 27 seconds of silence in honor of the victims of last week's shooting rampage in Connecticut.
"I know my mother would have been heartbroken to hear about something like that," he said. "Because even though for me, it was a tragedy to lose my mother at 27 years old, there were mothers who lost their children before they got the chance to find out who they were going to be, whether they were going to be singers or doctors. ... They didn't have a chance to live."
Read more: America missed out on getting to know Jenni Rivera
Plane company investigation
Rivera performed at a concert in Monterrey on December 8 before boarding the Learjet early the next day. It lost contact with air traffic controllers about 60 miles into the trip.
The small plane was 43 years old, the state-run Notimex news agency reported, citing the Mexican director of civil aviation.
The Drug Enforcement Administration is investigating the company that owned the plane.
Court records showed that the aviation company, Starwood Management, had two planes seized this year. The DEA declined to give further details, citing an ongoing investigation.
But it confirmed that the company was in a dispute with insurance firms over accusations of of falsehoods. Starwood and its representatives have not responded to repeated CNN requests for comments.
The U.S. National Transportation Safety Board said it is helping with the investigation.
U.S. records show the airplane was substantially damaged in 2005 when it struck a runway marker near Amarillo, Texas. At the time, the plane's pilot reported losing the ability to steer while landing the plane.
As the investigation into what caused the crash continues, family members said Wednesday that they were grateful to fans for their support and were committed to honoring Rivera's legacy.
"The best thing you ever taught me is when you fall, you get back up," daughter Jacqie Melina Campos said. "So that's what I'm going to do."
As the ceremony drew to a close, confetti fell onto the stage, and family members and fans covered Rivera's casket with white roses.
A band played the last few bars of "I Will Survive" before a recording of Rivera's voice boomed through the speakers.
Owner of plane in Jenni Rivera crash under DEA investigation
Journalist Victor Badillo, CNNMexico.com and CNN's Rafael Romo, Jim Barnett, Guillermo Arduino and Leslie Tripp contributed to this report.