Kimberly Stewart thinks it's ''crazy'' that the Kardashians have become the world's most famous family.

The 35-year-old daughter of rockstar Rod Stewart attended the renowned Buckley School in Sherman Oaks, California, with two of the stars and is surprised but impressed that the illustrious clan have become social media icons.

Kimberly said: ''I went to school with Kim and Kourtney, and I think it's amazing what they've done. It's crazy to think that they are the most famous family in the world. But every family is different.''

The pretty blonde shot to fame in her own eponymously named show in 2010 and is set to rejoin the reality TV scene tonight (27.05.15) on E! in a new fly-on-the wall series - entitled 'Stewarts & Hamiltons' - that will rival 'Keeping up with The Kardashians'.

And Kimberly - who has a three-year-old daughter, Delilah, with former flame and 'Guardians of the Galaxy' actor Benicio del Toro - admits that people will draw similarties between herself and her old school pals.

She told the Sunday Times Style magazine: ''We are a large, mixed family, so there will be some comparison.''