Writing on her personal blog last month, the English Literature graduate said that she was not a fan of EL James's novel.
"One book you can't judge by its cover (as it is quite impossible to prepare yourself for what lies inside) is Fifty Shades of Grey," Sears said.
"Proof of this is that my brother 'stumbled' across it when downloading books for his kindle, according to Mum. Worse still is now knowing that my mother has read it too."
She added: "Luckily Dad doesn't own a kindle, or possess the adequate know-how to download anything...
"Don't worry, I'm not here to masquerade as a literary critic, but I do want to say that I was left cold by the book and you can do much better for summer reading."
Sears went on: "My all-time favourite author/general superhero is Jilly Cooper; although to label her as 'summer reading' does her a complete disservice.
"I would have honestly written my dissertation on her if I was permitted... I own two copies of Polo because on the third time of reading I had to hold the book together with a clothes peg as all the pages were dropping out."
Sears was embraced by Murray in the Wimbledon crowd yesterday (August 5) after he defeated Roger Federer in straight sets to win the London 2012 Olympic gold medal in the tennis men's singles.
Photo gallery - London 2012 Olympics: