The reality star is scheduled to release I Just Want You to Know: Letters to My Kids on Love, Faith and Family on April 13 by Zondervan Publishers. The personal book will feature prayers, excerpts from her journal and eight individual letters addressed to each one of her children.

"Each day the thought crosses my mind that when they get older, my kids are going to look back and think about how they were raised," Gosselin says in a statement. "I know they will have a lot of questions about things that may not make sense because they were raised so unconventionally. I don't want them to grow up and wonder; I want them to know without a shadow of a doubt how much I love them and how much every sacrifice made was worth it for them."

Maureen "Moe" Girkins, CEO of Zondervan, said the company, a division of News Corp.'s HarperCollins publishing company, was going to "work with Kate to reassess the schedule for her next book."

"We are saddened by this news from the Gosselins and will continue to lift both Jon and Kate and their children up in prayer. We respect their need for time to focus on their family during this difficult time."

The Gosselins announced a separation Monday (June 22) during an episode of their popular TLC network show. They later issued a statement saying divorce papers had been filed. The show is on hiatus until Aug. 8