Riley Keough and her husband Ben Smith-Petersen secretly welcomed a baby girl, a rep for the actress confirmed to Fox News Digital on Sunday.

Smith-Petersen hinted at the news while reading a letter from the 33-year-old at a ceremony honoring his late mother-in-law, Lisa Marie Presley, held in Graceland.

"Thank you for showing me love is the only thing that matters in this life," he read." I hope I can love my daughter the way you loved me, the way you loved my brother and my sisters."

"Thank you for giving me strength, my heart, my empathy, my courage, my sense of humor, my manners, my temper, my wildness, my tenacity," the letter continued. "I’m a product of your heart, my sisters are a product of your heart, my brother is a product of your heart."

LISA MARIE PRESLEY HONORED AT GRACELAND IN PUBLIC MEMORIAL

Riley Keough and her husband Ben Smith-Petersen at a red carpet engagement

Ben Smith-Petersen and Riley Keough married in 2015. A rep for the actress confirmed to Fox News Digital on Sunday that the couple secretly welcomed a baby girl. (Getty Images)

No further details were provided by Keough’s rep, including when the baby was born or her name.

Smith-Petersen and Keough said "I do" in 2015.

Hundreds of people gathered on the front lawn of Graceland in Memphis, Tennessee, to mourn the death and remember the life of Elvis Presley's only child.

Lisa Marie, a singer-songwriter who dedicated her life to her father’s legacy, died on Jan. 12, hours after being hospitalized for a medical emergency. She was 54. Lisa Marie is survived by three daughters, including Keough.

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Ben Smith-Petersen reading a letter from Riley Keough

Ben Smith-Petersen read a tribute by Riley Keough, Lisa Marie Presley's daughter, at the public memorial for Lisa Marie Presley on Jan. 22, 2023, in Memphis, Tennessee. (Jason Kempin/Getty Images)

Some mourners held flowers as they waited for the service to begin under the tall trees on the lawn of Graceland, the home where Lisa Marie lived as a child with her father. The mansion, which she owned, has been turned into a museum and tourist attraction that hundreds of thousands of fans visit each year to celebrate the life and music of Elvis, who died in 1977.

"We would like to express our heartfelt gratitude for the love, compassion and support you have shown our family during this difficult time," said a message from the Presley family written on the program for the service. "We will always be grateful."

Riley Keough and Lisa Marie smiling on a red carpet together

Riley Keough and Lisa Marie Presley arrive at Elle's 24th Annual Women in Hollywood Celebration on Oct. 16, 2017, in Los Angeles, California. (Jon Kopaloff/FilmMagic)

Among those who made an appearance during the service were Priscilla Presley, Sarah Ferguson, the Duchess of York, as well as singers Billy Corgan, Alanis Morissette and Axl Rose.

LISA MARIE PRESLEY'S DAUGHTER RILEY KEOUGH BREAKS SILENCE ON HER DEATH WITH TOUCHING THROWBACK PHOTO

After the service, mourners made a procession through Graceland’s Meditation Garden, where Lisa Marie is being laid to rest.

The Associated Press contributed to this report.