When my husband and I were working to finalize the adoption of our little one, our case worker and kiddo's therapist suggested a number of books to help normalize and explain adoption to our child. Two years later, we still read the books when we see our child struggling with a topic. I think the same approach would be helpful in explaining and normalizing the confusing family changes that accompany dementia joining the family.
While my children and I have had numerous conversations about the changes in Lyn's brain, it may help them to see that our situation is common enough that someone has written a book on the topic. This approach will be more helpful to my little one though I think my eldest child will benefit as well.
So, if this concept is of help in your own family, here are some books we can use.
What's Wrong with Grandpa?: a children's story about Alzheimer's Disease by Danielle Sara Cohen
Wilfrid Gordon McDonald Partridge by Mem Fox
A Visit to Grandma's with Dignity and Grace by Terri L. Glimcher
Hugging Grandma: Loving Those with Memory Disorders by Zina Kramer
Grandpa Has Changed by Jennifer Moore-Mallinos
Got Dementia? by Heather Pritchard
The Shadows at Sundown by Michael Rock
Always My Grandpa by Linda Scacco
Striped Shirts and Flowered Pants: A Story about Alzheimer's Disease for Young Children by Barbara Schnurbush
What's Wrong with Grandma? A Family's Experience with Alzheimer's by Margaret Shawver
What's Happening to Grandpa by Maria Shriver
Visiting Poppi by Judy Spitzer
Still My Grandma by Veronique Van Den Abeele
My Grandma Has Alzheimer's Too by Joseph Voight
Why Did Grandma Put Her Underwear in the Refrigerator by Max Wallack
Not all of these books are about a specific disease that causes dementia like Alzheimer's. They address the generic concept of dementia and may prove useful if your family member is dealing with Lewy Body Dementia or another dementia causing disease.
Another resource you might find useful is the Kids and Teens page at the Alzheimer's Association. It has links to videos and other resources for the youth in your lives.
Looks like I need to do a little shopping. And this, lovely readers, is why a dear friend who helped us move once declared he never wanted to help a literate friend move again. That was said after about 60 boxes of books were loaded into the moving van. For those who prefer electronic versions, several of the books are available in Kindle format.