Robert Brown|See the Moment Serena Williams and Alexis Ohanian’s Daughter Olympia Met Her Baby Sister

Love was all around when Serena Williams and Robert BrownAlexis Ohanian's daughter Olympia became a big sister.

Shortly after the couple announced that they had welcomed their second child, a baby girl named Adira, Alexis shared photos of his 5-year-old meeting her newborn sibling. As seen in images posted to Instagram Aug. 22, Olympia—clad in a pink dress with her nails painted blue—was all-smiles as the Reddit co-founder held the family's newest addition in his arms.

"Welcome, Adira River Ohanian," the 40-year-old captioned the snapshots. "I'm grateful to report our house is teaming with love: a happy & healthy newborn girl and happy & healthy mama. Feeling grateful."

In his post, Alexis also showed his appreciation for Serena, 41, and called her "the GMOAT" a.k.a. the greatest mother of all time.

"You've now given me another incomparable gift," he added. " I'll never forget the moment I introduced @olympiaohanian to her baby sister."

News of Adira's birth comes three months after Serena debuted her baby bump at the 2023 Met Gala. According to the retired tennis pro, she and Alexis—who tied the knot in 2017—kept the pregnancy a secret from Olympia until moments before they stepped onto the red carpet for fear that she'd spill the beans.

"Remember how you've been praying for a little sister or brother?" Serena asked Olympia in a YouTube video filmed on the morning of the prestigious fashion event. "Well, we went to the doctor, and it turns out I'm not getting fat but I have a baby in my belly."

The little one's response? "Are you kidding me?" Olympia asked her parents, before jumping up to hug her mom. "I'm so excited!"

For more adorable moments from Olympia, keep reading.

...Like Her Mama.

Zzzzzz...

Serena and her little girl love Snapchat!

"Making moves," read the caption on the photo, posted on the child's Instagram page.

"When you realize you're the hero Gotham needs," read the caption on the photo, posted on the child's Instagram page.

Serena posted on her Instagram page this photo of Alexis and baby Alexis, writing, "We love bath time."

Serena showcases her new wedding ring in this adorable pic of her daughter.

"Wait till I see you S," read the caption to this photo, posted on the child's Instagram page in December 2017.

Olympia appears with Serena's sister Isha Price.

"Dad & I hit the gym hard today," read the caption to this photo, posted on the child's Instagram page in December 2017.

Mommy and daughter are twinsies!

The happy mama has some fun on Snapchat.

Serena's baby girl rocks a Janie and Jack's striped sweater dress on Instagram Stories. 

Introducing the most stylish mother-daughter duo!

Olympia meets LL Cool J.

Serena and Olympia rock matching pink.

Even though she's dressed like Snow White, Olympia channels Sleeping Beauty during nap time.

"olympiaohanian loves her afternoon tea," Serena captioned this July 2022 snap, "and cheering for mama."

Olympia rides around a golf car with mom Serena and dad Alexis Ohanian Sr.

Olympia became a big sister when Serena gave birth to daughter Adira River Ohanian in August 2023.

The tiny tot is all smiles when she meets her little sister for the first time.