Aspiring model and singer Ruby Stewart has admitted that she and her sister Kimberly did not speak for years while they were growing up.

The willowy sisters spent a large part of their childhood living separate lives with no contact.

It is only in the last few years, Ruby claimed in a recent interview, that the two have become close.

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Smoking siblings: Kimberly and Ruby weren't always so close

Ruby also took a while to get used to new step-mother Penny Lancaster, worried she would be a "wicked witch" after marrying the veteran rock star.

Kimberley, 26, is the product of 61-year-old Stewart's first marriage to Alana Hamilton, and a regular face on the British and US party circuit, her sister Ruby was not so well known until her recent modelling campaign for lingerie company Ultimo.

Both girls are models, although 18-year-old Ruby - the daughter of Texan model Kelly Emberg whose fling with Stewart ended his marriage to Miss Hamilton - is keen to pursue a musical career.

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Ruby modelling for the lingerie brand Ulimo

Ruby told Look Magazine: "I love Kimberly to death, but there was a point when we were younger when we didn't talk"

"It was partly because of our ages and we lived in a different place."

Rod married Penny Lancaster in June 2007, after his failed marriage to Rachel Hunter, making it difficult for Ruby to adapt to the change in mother figures.

"At first we thought Penny was going to be a wicked witch, but she came into our house acting like a mum, and she tucked us in at night, so we didn't torment her.

"No I love Penny, she's calm and sweet."

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Wicked witch: Rod with wife Penny Lancaster