Riley Keough Returns Home with Daughter After Lisa Marie Presley's Funeral

Riley Keough is back home in Los Angeles after burying her mother Lisa Marie Presley at Graceland, and she's revealing Lisa's first grandchild -- the daughter very few people knew Riley gave birth to last year.

The actress stepped off a private jet Monday afternoon at Van Nuys Airport, carrying her baby girl in her arms -- marking the first time we've seen her child in public.

Riley and her Hollywood stunt man husband, Ben Smith-Petersen, made the surprise reveal about their daughter's existence during Lisa Marie's celebration of life ... when Ben read a letter Riley wrote to her mom, which referenced the little girl.

The letter, which Riley entitled "A Letter to My Mama," reads in part ... "I hope I can love my daughter the way you loved me, the way you loved my brother and my sisters."

Ben and Riley had never gone public about having a baby, and, obviously, Riley did a top-notch job of keeping her pregnancy private.