The Father of the Bride star first opened up about her mum Linda's struggle with dementia in a Redbook magazine essay in 2014, and now she has turned her personal experience with the progressive disease into a memoir, titled, Where the Light Gets In: Losing My Mother Only to Find Her Again.

During a new interview on U.S. breakfast show Today to promote her book, Kimberly admitted pouring out her emotions for the tome proved to be a good form of therapy.

"After so many years of feeling like I have to be private and secret, it was just so empowering to be able to take the reigns of the story and open my heart and sharing my journey and then growing and feeling stronger because I've come through the other end," she explained.

In the book, Kimberly reveals her father, Gurney, has since found love with another woman, and although it was initially tough for her and her siblings to accept, they are now thankful his girlfriend, Nancy, is able to support him emotionally as Linda's Alzheimer's disease worsens.

"That was hard because my mum is still alive and they're still married, and my father met somebody and was in love," she stated. "(But) she, Nancy, is a real blessing for all of us, because she is there for him in a way that my siblings and I can't be right now."

And Kimberly has also found strength in her singer husband Brad, whose support has been invaluable throughout her mother's health battle.

"I'll have moments when I completely break down and can't handle it anymore and there he is to hold me, and more often, he's there to make me laugh in the middle of a really hard day," she smiled.

The celebrity couple has also used the experience to openly discuss its own hopes and concerns for the future so Kimberly and Brad can be more prepared if they ever face similar health struggles.

She added, "We worry about it (dementia) happening to both of us; it's in both of our families but we're just trying to have those kind of honest conversations that I wish I'd had with my mum, about what we want to have happen if that is the situation."