When you think of female rivalry in the royal family, it's always between Meghan Markle and Kate Middleton. 

Though the two are being pitted against one another, the Duchess of Cambridge reportedly has felt more rivalry from somebody else. 

Kate has always been close to her sister, Pippa Middleton. Apparently, the two sisters speak to each other every other day. 

However, she is not immune to sibling rivalry. The two Middleton sisters have always been competitive with each other ever since they were younger. 

Kate Nicholl reported in 2011, "There was always that thing of who could be the thinnest, and who could be the prettiest." 

Though everybody knows that Kate Middleton is the prettier sister, since she was able to charm Prince William, someone who also exudes elegance and confidence, a report claimed that she was not as confident as she is now. 

"Even though she had secured the most sought-after boy at St. Andrews, she never gloated. She was actually quite insecure about her looks and never considered herself pretty. She was very sweet and very shy." 

In fact, it was reported that the Duchess was jealous of her sister Pippa. 

In Kate Middleton and Prince William's royal wedding, the older sister was flabbergasted at how much focus was given to her sister instead of her. 

But Pippa felt terrible and speaking to Today in 2014, and she revealed how it was flattering but embarrassing to get that much attention at her sister's wedding.

The real reason all eyes were on Pippa was because of the simplicity of the dress she wore, which looked so insignificant to the Duchess of Cambridge's lavish wedding dress. 

Journalist Emma Cowing wrote in The Scotsman, "I sensed that Kate feared being eclipsed by her because Pippa has more natural effervescence, she is socially much more at ease and was always popular with everyone, especially with James' friends." 

When Pippa later enrolled at St. Andrews, she quickly formed a huge circle of friends.

"As soon as Pippa arrived at Edinburgh, she was assiduous about joining the right social circle. She was very charming about it, but quite ruthless in cultivating the right friends," Cowing said. 

Sports coach Denis Alford told royal expert Katie Nicholl that though they were competitive and had the drive, especially Pippa, the two sisters were very much a team. 

Kate and Pippa Middleton, though they get along well, the two are reportedly so different. 

It was reported that Pippa once used the alias Lucy Middleton to call for a cab who need to be picked up in a bar. The cab driver told the Daily Mail, "She ordered a taxi for Lucy Middleton and kept ringing, asking if I was there yet because she was hiding in a dark doorway." 

The driver later Googled the name and saw that Lucy is the cousin of the two sisters, and in the picture was Pippa. 

"It was actually Pippa in my cab."

Why Pippa was so keen to hide her identity remains a story. But one thing is for sure, the Duchess of Cambridge will never do anything like that.

She already has a family of her own and is about to become Queen Consort to Prince William when he becomes king.  

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