Meghan Markle's Friend Lindsay Jill Roth Honors Their 'Unbreakable Bond' in New Book

"She hasn't read her acknowledgement yet," Roth, an author and television producer, previously told PEOPLE about the message for Meghan in the dedication

Meghan Markle‘s longtime friend Lindsay Jill Roth is honoring their friendship with a special tribute in her new book — kept a secret until release day.

“She hasn’t read her acknowledgement yet,” Roth, an author and television producer, previously told PEOPLE about the message for Meghan in the dedication of Romances & Practicalities: A Love Story (Maybe Yours!) in 250 Questions, out Jan. 28.

“I have saved that as a little token for her to see when the book comes out. I think it’s rare to find friends who love you unconditionally, and I’ve been lucky in my life to have a few who I truly consider family,” she said. “It’s almost like those words aren’t enough.”

Roth and Meghan met as freshmen at Northwestern University in a Toni Morrison literature class, and their bond blossomed into a close friendship honored in the acknowledgements of Romances & Practicalities.

In her dedication, Roth wrote: “Meghan Sussex, Meg, to be sisters by choice, still thinking the same thing at the same time after all these years — no matter how many miles between us — is my favorite part of our unbreakable bond,” Roth wrote. “There for each other always, sharing a deep loyalty and understanding — I could tell you anything, and it would be okay. I carry your heart (I carry it in my heart).”

The Duchess of Sussex, 43, served as the maid of honor when her friend married Gavin Jordan (a Brit like Prince Harry!) in 2016, and that transatlantic courtship inspired Roth to put pen to paper for her new book, designed to help readers find the love of a lifetime.

In it, the former Larry King Now producer weaves own romantic journey with expert-backed guidance, pitching a collection of 250 questions to foster deeper rapport and help people identify what they really want in a partner.

“I was like the girl from 27 Dresses — I had tried to find my person, and I thought I was ready. Until I really looked at myself and asked, ‘What are you really looking for? Not just what are you looking for on paper, but what is going to be the best for you?'” Roth previously told PEOPLE around the book’s exclusive cover reveal in October.

Roth’s message to Meghan notably referenced her friend by her official surname: Sussex. Though the Duchess of Sussex is popularly known by her maiden name, it emerged last year that she and Harry adopted their Duke and Duchess of Sussex titles as the last name for their children.

PEOPLE understands that Sussex is the family surname. Using their titles as their children’s last names follows longstanding tradition used by members of the royal family.

Like Meghan, Roth married an Englishman and went on to welcome two children together. Roth and Jordan live between New York and London with their two young sons, while Prince Harry and Meghan are raising their kids Prince Archie, 5 and Princess Lilibet, 3, in her home state of California.

Commenting on the coincidence that she and Meghan both married partners from the U.K., Roth told PEOPLE that she prefers to underscore what matters most.

“I often get asked, ‘Is it really special that you both married Brits?’ What I always say is, ‘It’s special that we both married such wonderful people,'” Roth said about the serendipity. “I’m lucky to have chosen a partner who is so supportive of the stories I want to tell and of me. He’s been along for the ride the whole time.”

Romances & Practicalities: A Love Story (Maybe Yours!) in 250 Questions is published by HarperCollins, and available for sale now wherever books are sold.