United Kingdom, Sept. 1 -- Harper Beckham has praised her brother Romeo as her "role model".

The 15-year-old star, whose parents are David and Victoria Beckham, has paid tribute to her older brother to mark his 24th birthday on Tuesday (01.09.26) with a sweet social media post.

She wrote on Instagram: "Today is all about celebrating you, and I hope you know how loved and appreciated you are.

"You'll always be one of the biggest role models in my life, and I'll forever look up to you and everything you are.

"I'm so lucky to have you as my brother, and I genuinely don't know what I'd do without you.

"Thank you for always being someone I can look up to and be proud of. I hope this year brings you so much happiness, love, and everything ...