EXCLUSIVE: Meghan Markle's Sister Reveals Her 'Normal' Upbringing, Likens Her to Princess Diana

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While Meghan Markle has struck up a royal romance with Prince Harry, the Suits star's half-sister, Samantha Grant, says she comes from humble, down-to-earth roots.

Grant, who shares the same father with Markle, is 17 years older than her, but despite their age difference the two were very close growing up.

"She was never a partier, she worked very hard," Grant recently shared with ET. "She was studious, she was brilliant in her studies, she was brilliant on stage, she is world traveled."

"At a young age, she was thrust into this position of requiring her to be articulate and graceful and worldly and mature," she continued. "She's definitely strong enough to embrace gracefully whatever challenges come her way."

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While Markle may not be royalty, Grant says her sister certainly has a regal essence, explaining, "She's got the eloquence of a Condoleezza Rice, and the grace of Princess Diana."

"She's not wild, she's not garish, she's not a partier," she added. "She's just very beautiful and conservative, very real, very giving. She's just a peaceful person."

Markle, 35, grew up in Woodland Hills, California, with loving parents and a supportive, nurturing environment.

"She went to a private elementary school and high school and then college," Grant recounted. "It was very normal."

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Recently, Markle penned an editorial for Elle UK, in which she opened up about her own humanitarian work and the role her parents played in making her the person she is today.

"My parents came from little so they made a choice to give a lot: buying turkeys for homeless shelters at Thanksgiving, delivering meals to people in hospices, giving spare change to those asking for it," she continued. "It's what I grew up seeing, so it's what I grew up being: a young adult with a social consciousness to do what I could and speak up when I knew something was wrong."

It's that loving home life Markle enjoyed that makes Grant upset when she reads tabloids trying to embellish the fairy tale story of her relationship with Prince Harry.

"When the media suggested that [her parents] were anything less [than great], and that she was this Cinderella that just rose up out of rubbish or out of nowhere -- no, that is rubbish," Grant explained. "Her parents were incredible."

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As for her new royal British boyfriend, Grant says that Markle has always been a very independent, self-determined woman, and Harry's linage doesn't play a part in Markle's feelings towards him.

For Markle to truly be happy and emotionally satisfied, it would "take a really great man," her sister said. "Someone who is of incredible character and [has a] sense of adventure and romance and all of those things that we would want in a Prince Charming."

Check out Entertainment Tonight’s full interview with Grant on Wednesday to hear what she thinks the tabloids have gotten wrong about Markle’s royal romance. Check here for local listings.

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Earlier this month, Markle and her beau spent time together across the pond where the actress reportedly met with Prince Harry's brother, Prince William, and his wife, the Duchess of Cambridge.

For more on the cute couple's U.K. vacay, watch the video below.