Katie Taylor and Amanda Serrano will duke it out when they headline an all-women's boxing card at Madison Square Garden on July 11. While a lot of the focus will be on the action in the ring, fans who tune in may see a familiar face in between rounds.
Kourtney Kellar will be making her return to being a ring girl for the fight. She is the wife of Oklahoma City Thunder center Isaiah Hartenstein and is a professional model. Kellar has been a ring girl several times in the past but is making her return to the ring for the first time since she was pregnant and had her and Hartenstein's son Elijah in 2024.
Here is more on Kellar, who will be serving as a ring girl for the Katie Taylor vs. Amanda Serrano fight.
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Who is Isaiah Hartenstein's wife?
Isaiah Hartenstein is married to model Kourtney Kellar. She was born in Texas, grew up in the Dallas area and is a lifelong basketball fan, growing up and supporting the Mavericks.
She went to Henderson State University in Arkansas and graduated in 2014. Kellar started modeling to help pay for school for companies like Dillards and Walmart, she told the New York Post in an October 2022 interview. She was previously engaged to music star Chase Bryant, but they called off their engagement after being together since 2015.
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Kourtney Kellar modeling
Kellar competed in the Miss Henderson State University pageant in 2013 and 2014. Kellar then competed in Miss Texas International and won it in 2017.
Kellar signed with Lipps LA and Select Miami in 2021. This has allowed her to walk in Miami Swim Week and New York Fashion Week. And she graced the cover of Malvie Magazine.
Ring girl history
After being named Miss Texas International in 2017, she became a model for Supercross with Rockstar. Kellar also became a ring girl, affiliated with Tecate. You may have recognized her if you tuned into the Canelo Alvarez vs. Gennady Golovkin III fight in 2018, as it was her first match as a ring girl.
She went viral on social media in 2021 as well. Kellar was the ring girl when Jake Paul fought Tyron Woodley. Fans were quick to see that it looked like Jake's brother Logan was flirting with the ring girl in the background.
Kellar is going to be a ring girl for the upcoming bought between Katie Taylor and Amanda Serrano, and she talked about the opportunity during an interview at the NBA Finals.
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How did Isaiah Hartenstein and Kourtney Kellar meet?
If you've heard the term "shoot your shot," that's what Isaiah Hartenstein did. He slid into Kellar's Instagram DMs. She told the New York Post, "My Instagram is pretty sexy, so I get a lot of comments about my body, which is nice. But he came in and messaged me something like, 'You have the most beautiful smile,' and sent me his favorite photo of me from my feed. I was wearing a turtleneck in that picture. It was really sweet of him."
Before meeting up, Kellar wanted to confirm that Hartenstein was real and get his vibe. He was playing for the Rockets at the time, so he wasn't far away. Ahead of meeting, Kellar and Hartenstein FaceTimed a few times before meeting in person. She said, "I confirmed he wasn't a serial killer, and we met up at a restaurant. It went so great, and I was really excited."
They got engaged in April 2022 when Hartenstein proposed to Kellar in Malibu. They married in July 2023.
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Do Isaiah Hartenstein and Kourtney Kellar have kids?
Yes, the couple has one child, a son. They welcomed Elijah James on May 23, 2004. The young Hartenstein stole the show after the Thunder won the 2025 NBA Finals. He was so tuckered out, he couldn't stay awake. Hartenstein was celebrating, and the MVP Shai Gilgeous-Alexander had to remind him to support his kid's neck because he had flopped over in his dad's arms.
Isaiah Hartenstein's son was KNOCKED OUT during OKC's trophy presentation 🤣😴 pic.twitter.com/UbKEto9FvB
— Bleacher Report (@BleacherReport) June 23, 2025
Kourtney Kellar on social media
Kellar is an influencer on social media. She regularly posts about life, being a model and being married to an NBA player. Kellar has 444,500 followers on TikTok and 659,000 on Instagram.
@kourtney_kellar Best.Day.Ever. So proud of you Zay! #nbachampion #okcthunder #isaiahhartenstein ♬ Smokeufoos Audio - Smokeufoos
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