Meghan Markle's estranged half-sister Samantha Grant has come forward at a very convenient time to publish her tell-all book about Prince Harry's girlfriend. The book, currently being written, is said to reveal Grant's relationship with Markle and some shocking truths about the actress.

According to E! News, a source stated that the 52-year-old Grant might have ulterior motives. Apparently, the book, the working title being "The Diary of Princess Pushy's Sister," will focus on her and Meghan Markle's relationship even when they grew up with completely separate lives.

"Samantha Grant doesn't have a relationship with Meghan Markle and she never has," E! News quoted the source. "As they were 17 years apart, they were never raised in the same house. Meghan was raised an only child by her loving parents."

The source further added that Grant just wants to take advantage of being somehow related to Meghan Markle, since she is dating Prince Harry now. Rumors of the couple getting engaged soon have already started to go around with Princess Diana's birthday said to be the date.

The source stated that Grant, who has had a lifelong history of lying and manipulation, now wants to cash in on Meghan Markle's fame. The "Suits" actress had only a few interactions with her half sister and majority of it happened when she was just a little girl. The source claimed that the actress was nothing but nice to Grant on whatever handful occasions they have met.

However, according to The Sun, Samantha Grant has accused Meghan Markle of not giving her family any emotional and financial support when she became famous. She further stated that the truth behind the model and actress would destroy her relationship with Prince Harry. 

Interestingly, Grant has recently changed her last name to Markle. The source stated that this is a suspicious move since she has claimed not liking the American actress and yet trying to share an identity with her.